Three Months Ended
June 30,

Six Months Ended
June 30,

2011

2010

2011

2010

Net income

$

117.4

$

88.7

$

221.5

$

174.0

Basic:

Weighted-average shares outstanding

39.2

39.3

39.2

39.1

Basic net income per share

$

2.99

$

2.26

$

5.65

$

4.45

Diluted:

Weighted-average shares outstanding used in basic calculation

39.2

39.3

39.2

39.1

Add common stock equivalents

1.1

1.2

1.0

1.3

Weighted-average shares used in computing diluted net income per share

40.3

40.5

40.2

40.4

Diluted net income per share

$

2.91

$

2.19

$

5.51

$

4.31