15. Earnings Per Share

The following table sets forth the computation of basic and diluted earnings per share (in thousands, except per share data):


	Year Ended December 31,
	2010		2009		2008
Numerator for basic and diluted earnings per share — net income attributable to common stockholders	$	106,882	$	171,190	$	260,098

Denominator for basic earnings per share — weighted average shares		127,656		114,207		93,732
Effect of dilutive securities:
Employee stock options		125		—		82
Non-vested restricted shares		420		405		443
Convertible senior unsecured notes		7		—		52

Dilutive potential common shares		552		405		577
Denominator for diluted earnings per share — adjusted weighted average shares		128,208		114,612		94,309

Basic earnings per share	$	0.84	$	1.50	$	2.77

Diluted earnings per share	$	0.83	$	1.49	$	2.76

The diluted earnings per share calculations exclude the dilutive effect of 280,000, 351,000 and 0 stock options for the years ended December 31, 2010, 2009 and 2008, respectively, because the exercise prices were more than the average market price. The outstanding convertible senior unsecured notes were not included in the 2009 calculations as the effect of the conversions into common stock was anti-dilutive for that period. The Series H Cumulative Convertible and Redeemable Preferred Stock issued in 2010 were excluded from the calculation for 2010 as the effect of the conversions was anti-dilutive.