EARNINGS PER SHARE

Earnings Per Share. Basic income per share is computed based upon the weighted-average number of common shares outstanding, excluding unvested restricted stock. Diluted income per share is computed based upon the weighted-average number of common shares outstanding, including the dilutive effect of common stock equivalents outstanding during the periods. Potentially dilutive common stock equivalents primarily consist of employee stock options, unvested restricted stock, and restricted stock units (“Equity-based Incentive Awards”).

Potentially dilutive common shares from Equity-based Incentive Awards are determined by applying the treasury stock method to the assumed exercise of outstanding employee stock options, and the assumed vesting of outstanding unvested restricted stock and restricted stock units. The following table presents the weighted-average number of common shares outstanding used in the calculation of basic and diluted income per share:



	Three Months Ended September 30,		Nine Months Ended September 30,
	2011	2010	2011	2010

Weighted-average common shares outstanding - basic	41,292,819	32,794,553	39,178,952	31,776,074
Dilutive effect of Equity-based Incentive Awards	1,565,061	2,310,800	1,554,861	2,672,592
Weighted-average common shares outstanding - diluted	42,857,880	35,105,353	40,733,813	34,448,666

Anti-dilutive Equity-based Incentive Awards excluded from the computation of diluted income per share	30,000	64,768	46,560	250,336