The following table sets forth the computation of basic and diluted net income per share for the periods indicated (amounts in thousands):

				Year Ended December 31,
				2011	2010	2009

Shares used in basic earnings per share calculation				56,669	60,361	62,891
	Effect of dilutive securities:
		Stock options		727	874	814
		Restricted stock units		564	557	533
		Performance-based restricted stock units		3	-	-
			Total effects of dilutive securities	1,294	1,431	1,347
Shares used in dilutive earnings per share calculation				57,963	61,792	64,238

For the years ended December 31, 2011, 2010 and 2009, 0.1 million, 0.1 million and 0.4 million, respectively, of options to purchase shares of common stock were outstanding but not included in the computation of diluted net income per share because the exercise price exceeded the value of the shares and the effect would have been anti-dilutive. For the years ended December 31, 2011, 2010 and 2009, restricted stock units of 0.6 million, 1.1 million, and 0.8 million, respectively, were outstanding but not included in the computation of diluted net income per share because the effect would have been anti-dilutive. For the years ended December 31, 2011, 2010 and 2009, there were no performance-based restricted stock units outstanding but not included in the computation of diluted net income per share. For the years ended December 31, 2011, 2010 and 2009, restricted stock units that vest based on the Company achieving specified operating income performance targets, of 0.1 million, 0.1 million and 0.1 million, respectively, were outstanding but not included in the computation of diluted net income per share because they were not determined to be contingently issuable.