[1]

Market stock units (MSUs) granted during the nine months ended September 30, 2012 include approximately 39,000 and 41,000 MSUs issued in 2012 based upon the attainment of performance criteria set for 2011 and 2010, respectively, in relation to shares granted in those years. The remainder of MSUs granted during the nine months ended September 30, 2012 include awards granted in conjunction with our annual awards made in February 2012 and MSUs granted in conjunction with the hiring of employees. These grants reflect the target number of shares eligible to be earned at the time of grant.MSUs granted during the nine months ended September 30, 2011, include approximately 26,000 MSUs issued in 2011 based upon the attainment of performance criteria set for 2010 in relation to shares granted in 2010. The remainder of MSUs granted during the nine months ended September 30, 2011 include awards granted in conjunction with our annual awards made in February 2011 and MSUs granted in conjunction with the hiring of employees. These grants reflect the target number of shares eligible to be earned at the time of grant.

[2]

Cash settled performance shares (CSPSs) granted during the nine months ended September 30, 2012 include approximately 68,000 CSPSs issued in 2012 based upon the attainment of performance criteria set for 2011 in relation to shares granted in 2011. The remainder of CSPSs granted during the nine months ended September 30, 2012 include awards granted in conjunction with our annual awards made in February 2012 and CSPSs granted in conjunction with the hiring of employees. These grants reflect the target number of shares eligible to be earned at the time of grant.CSPSs granted during the nine months ended September 30, 2011, include approximately 95,000 CSPSs issued in 2011 based upon the attainment of performance criteria set for 2010 in relation to shares granted in 2010. The remainder of CSPSs granted during the nine months ended September 30, 2011 include awards granted in conjunction with our annual awards made in February 2011 and CSPSs granted in conjunction with the hiring of employees. These grants reflect the target number of shares eligible to be earned at the time of grant.

[3]

Time-vested restricted stock units (RSUs) granted during the nine months ended September 30, 2012 primarily represent RSUs granted in conjunction with our annual awards made in February 2012 and awards made in conjunction with the hiring of new employees. RSUs granted during the nine months ended September 30, 2012 also include approximately 24,000 RSUs granted to our Board of Directors. RSUs granted during the nine months ended September 30, 2011 primarily represent RSUs granted in conjunction with our annual awards made in February 2011 and awards made in conjunction with the hiring of new employees. RSUs granted during the nine months ended September 30, 2011 also include approximately 35,000 RSUs granted to our Board of Directors.

[4]

Performance-vested restricted stock units (PVRSUs) granted during the nine months ended September 30, 2011 represent shares earned for performance criteria set for 2010 in relation to shares granted in 2010. No PVRSUs were granted during the nine months ended September 30, 2012.