<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"><Version>2.2.0.25</Version><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><ReportLongName>0203 - Disclosure - Earnings per Share</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelColumn>false</LabelColumn><CurrencyCode>USD</CurrencyCode><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName>1/1/2010 - 12/31/2010
USD ($)

USD ($) / shares

</KeyName><CurrencySymbol>$</CurrencySymbol><contextRef><ContextID>TwelveMonthsEnded_31Dec2010</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0001458891</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2010-01-01T00:00:00</PeriodStartDate><PeriodEndDate>2010-12-31T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS><UnitProperty><UnitID>Pure</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>pure</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>USD</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>USDEPS</UnitID><UnitType>Divide</UnitType><NumeratorMeasure><MeasureSchema>http://www.xbrl.org/2003/iso4217</MeasureSchema><MeasureValue>USD</MeasureValue><MeasureNamespace>iso4217</MeasureNamespace></NumeratorMeasure><DenominatorMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>shares</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></DenominatorMeasure><Scale>0</Scale></UnitProperty><UnitProperty><UnitID>Shares</UnitID><UnitType>Standard</UnitType><StandardMeasure><MeasureSchema>http://www.xbrl.org/2003/instance</MeasureSchema><MeasureValue>shares</MeasureValue><MeasureNamespace>xbrli</MeasureNamespace></StandardMeasure><Scale>0</Scale></UnitProperty></UPS><CurrencyCode>USD</CurrencyCode><OriginalCurrencyCode>USD</OriginalCurrencyCode></MCU><CurrencySymbol>$</CurrencySymbol><Labels><Label Id="1" Label="12 Months Ended" /><Label Id="2" Label="Dec. 31, 2010" /></Labels></Column></Columns><Rows><Row><Id>2</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><Level>0</Level><ElementName>us-gaap_EarningsPerShareAbstract</ElementName><ElementPrefix>us-gaap</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole /><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><NonNumericTextHeader /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>No definition available.</ElementDefenition><IsTotalLabel>false</IsTotalLabel><IsEPS>false</IsEPS><Label>Earnings per Share [Abstract]</Label></Row><Row><Id>3</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><Level>0</Level><ElementName>us-gaap_EarningsPerShareTextBlock</ElementName><ElementPrefix>us-gaap</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><ShortDefinition>No definition available.</ShortDefinition><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsSubReportEnd>false</IsSubReportEnd><IsCalendarTitle>false</IsCalendarTitle><IsTuple>false</IsTuple><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><PreferredLabelRole>verboselabel</PreferredLabelRole><FootnoteIndexer /><Cells><Cell><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>
    &lt;!--DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" --&gt;
    &lt;!-- Begin Block Tagged Note 3 - us-gaap:EarningsPerShareTextBlock--&gt;
    &lt;div style="font-family: 'Times New Roman',Times,serif; margin-left: 0in; "&gt;
    &lt;div align="justify" style="font-size: 10pt; margin-top: 10pt"&gt;&lt;b&gt;Note 3 &amp;#8212; Earnings per Share&lt;/b&gt;
    &lt;/div&gt;
    &lt;div align="justify" style="font-size: 10pt; margin-top: 10pt; text-indent: 8%"&gt;Our unvested share-based payment awards, which include restricted shares and restricted units
    are considered participating securities as they contain non-forfeitable rights to dividends and
    should be included in the computation of earnings per share pursuant to the &amp;#8220;two-class&amp;#8221; method.
    The &amp;#8220;two-class&amp;#8221; method allocates undistributed earnings between common shares and participating
    securities. The diluted earnings per share calculation under the &amp;#8220;two-class&amp;#8221; method also includes
    the dilutive effect of potential share issuances in connection with stock options. The dilutive
    effect of stock options is determined using the treasury stock method.
    The following table sets
    forth the computation of basic and diluted net income per share for Noble-Swiss:
    &lt;/div&gt;
    &lt;div align="center"&gt;
    &lt;table style="font-size: 10pt; text-align: left" cellspacing="0" border="0" cellpadding="0" width="100%"&gt;
    &lt;!-- Begin Table Head --&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td width="58%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="3%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="1%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="9%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="1%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="3%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="1%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="9%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="1%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="3%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="1%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="9%"&gt;&amp;#160;&lt;/td&gt;
    &lt;td width="1%"&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 10pt" valign="bottom"&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="center" colspan="10" style="border-bottom: 1px solid #000000"&gt;&lt;b&gt;Year Ended December 31,&lt;/b&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 10pt" valign="bottom"&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="center" colspan="2" style="border-bottom: 1px solid #000000"&gt;&lt;b&gt;2010&lt;/b&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="center" colspan="2" style="border-bottom: 1px solid #000000"&gt;&lt;b&gt;2009&lt;/b&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="center" colspan="2" style="border-bottom: 1px solid #000000"&gt;&lt;b&gt;2008&lt;/b&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;!-- End Table Head --&gt;
    &lt;!-- Begin Table Body --&gt;
    &lt;tr valign="bottom" style="background: #cceeff"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&lt;b&gt;Allocation of net income&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:45px; text-indent:-15px"&gt;&lt;b&gt;Basic&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom" style="background: #cceeff"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:60px; text-indent:-15px"&gt;Net income attributable to Noble Corporation
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;773,429&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;1,678,642&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;1,560,995&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:60px; text-indent:-15px"&gt;Earnings allocated to unvested share-based
    payment awards
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="left"&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;(7,497&lt;/td&gt;
    &lt;td nowrap="nowrap"&gt;)&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="left"&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;(16,811&lt;/td&gt;
    &lt;td nowrap="nowrap"&gt;)&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="left"&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;(13,195&lt;/td&gt;
    &lt;td nowrap="nowrap"&gt;)&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 1px"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom" style="background: #cceeff"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:75px; text-indent:-15px"&gt;&lt;b&gt;Net income &amp;#8212; basic&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;765,932&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;1,661,831&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;1,547,800&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 1px"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;&lt;!-- Blank Space --&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:45px; text-indent:-15px"&gt;&lt;b&gt;Diluted&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom" style="background: #cceeff"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:60px; text-indent:-15px"&gt;Net income attributable to Noble Corporation
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;773,429&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;1,678,642&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;1,560,995&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:60px; text-indent:-15px"&gt;Earnings allocated to unvested share-based
    payment awards
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="left"&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;(7,481&lt;/td&gt;
    &lt;td nowrap="nowrap"&gt;)&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="left"&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;(16,758&lt;/td&gt;
    &lt;td nowrap="nowrap"&gt;)&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" align="left"&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;(13,131&lt;/td&gt;
    &lt;td nowrap="nowrap"&gt;)&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 1px"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom" style="background: #cceeff"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:75px; text-indent:-15px"&gt;&lt;b&gt;Net income &amp;#8212; diluted&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;765,948&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;1,661,884&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;1,547,864&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 1px"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;&lt;!-- Blank Space --&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:30px; text-indent:-15px"&gt;&lt;b&gt;Weighted average shares outstanding &amp;#8212; basic&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;253,123&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;258,035&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;264,782&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom" style="background: #cceeff"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:45px; text-indent:-15px"&gt;Incremental shares issuable from assumed
    exercise of stock options
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;813&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;856&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;2,023&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 1px"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:60px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 1px solid #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:30px; text-indent:-15px"&gt;&lt;b&gt;Weighted average shares outstanding &amp;#8212; diluted&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;253,936&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;258,891&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;266,805&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 1px"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;&lt;!-- Blank Space --&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom" style="background: #cceeff"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:30px; text-indent:-15px"&gt;&lt;b&gt;Weighted average unvested share-based
    payment awards&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;2,438&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;2,611&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="right"&gt;2,224&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr style="font-size: 1px"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td nowrap="nowrap" colspan="2" align="right" style="border-top: 3px double #000000"&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;&lt;!-- Blank Space --&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&amp;#160;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:15px; text-indent:-15px"&gt;&lt;b&gt;Earnings per share&lt;/b&gt;
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom" style="background: #cceeff"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:30px; text-indent:-15px"&gt;Basic
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;3.03&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;6.44&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;5.85&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;tr valign="bottom"&gt;
    &lt;td&gt;
    &lt;div style="margin-left:30px; text-indent:-15px"&gt;Diluted
    &lt;/div&gt;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;3.02&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;6.42&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;td align="left"&gt;$&lt;/td&gt;
    &lt;td align="right"&gt;5.81&lt;/td&gt;
    &lt;td&gt;&amp;#160;&lt;/td&gt;
    &lt;/tr&gt;
    &lt;!-- End Table Body --&gt;
    &lt;/table&gt;
    &lt;/div&gt;
    &lt;div align="justify" style="font-size: 10pt; margin-top: 10pt; text-indent: 8%"&gt;Only those items having a dilutive impact on our basic net income per share are included in
    diluted net income per share. For the years ended December&amp;#160;31, 2010, 2009 and 2008, stock options
    totaling 0.8&amp;#160;million, 0.1&amp;#160;million and 0.7&amp;#160;million, respectively, were excluded from the diluted net
    income per share calculation as they were not dilutive.
    &lt;/div&gt;
    &lt;/div&gt;
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    &lt;!-- Begin Block Tagged Note</NonNumericTextHeader><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios></Cell></Cells><OriginalInstanceReportColumns /><Unit>Other</Unit><ElementDataType>us-types:textBlockItemType</ElementDataType><SimpleDataType>string</SimpleDataType><ElementDefenition>This element may be used to capture the complete disclosure pertaining to an entity's earnings per share.</ElementDefenition><ElementReferences>Reference 1: http://www.xbrl.org/2003/role/presentationRef
 -Publisher FASB
 -Name Statement of Financial Accounting Standard (FAS)
 -Number 128
 -Paragraph 40

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