Exhibit 12.1

Ratio of Earnings to Fixed Charges



|                                                                |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |   |  |   |         |  |   |        
|--------------------------------------------------------------- |  | ------------------------------- | ------ | ------------------------ | - | ------- | - |  | ---- | ------- | - | ---- | - | ------- | - |  | - | ------- |  | - | -------
|                                                                |  | Three MonthsEndedMarch 31, 2008 |        | Years Ended December 31,
|                                                                |  |                                 |       
|                                                                |  |                                 | 2007   |                          |   | 2006    |   |  | 2005 |         |   | 2004 |   | 2003   
|                                                                |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |   |  |   |         |  |   |        
|(in thousands, except ratios)                                   |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |  
|                                                                |  |                                 |        |                          |   |        
|Income before income taxes and minority interest                |  | $                               | 43,885 |                          | $ | 202,009 | 4 |  | $    | 204,842 | 3 |      | $ | 230,100 | 2 |  | $ | 173,862 |  | $ | 86,035 
|Add fixed charges                                               |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |   |  |   |         |  |   |        
|Interest expense                                                |  |                                 | 918    |                          |   | 6,680   |   |  |      | 1,506   |   |      |   | 7,618   | 2 |  |   | 3,828   |  |   | 9,765  
|Interest portion of rent expense                                |  |                                 | 1,358  |                          |   | 5,576   |   |  |      | 5,753   |   |      |   | 6,280   |   |  |   | 6,185   |  |   | 6,113  
|                                                                |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |   |  |   |         |  |   |        
|Income before income taxes, minority interest and fixed charges |  | $                               | 46,161 |                          | $ | 214,265 | 4 |  | $    | 212,101 | 3 |      | $ | 243,998 |   |  | $ | 183,875 |  | $ | 101,913
|                                                                |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |   |  |   |         |  |   |        
|Fixed charges                                                   |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |   |  |   |         |  |   |        
|Interest expense                                                |  | $                               | 918    |                          | $ | 6,680   |   |  | $    | 1,506   |   |      | $ | 7,618   | 2 |  | $ | 3,828   |  | $ | 9,765  
|Interest portion of rent expense                                |  |                                 | 1,358  |                          |   | 5,576   |   |  |      | 5,753   |   |      |   | 6,280   |   |  |   | 6,185   |  |   | 6,113  
|                                                                |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |   |  |   |         |  |   |        
|Fixed charges                                                   |  | $                               | 2,276  |                          | $ | 12,256  |   |  | $    | 7,259   |   |      | $ | 13,898  | 2 |  | $ | 10,013  |  | $ | 15,878 
|                                                                |  |                                 |        |                          |   |         |   |  |      |         |   |      |   |         |   |  |   |         |  |   |        
|Ratio of earnings to fixed charges1                             |  |                                 | 20.3   |                          |   | 17.5    | 4 |  |      | 29.2    | 3 |      |   | 17.6    | 2 |  |   | 18.4    |  |   | 6.4    
|                                                               



|1 |  | Ratio of earnings to fixed charges means the ratio of income before fixed charges and income taxes to fixed charges, where fixed
charges are the aggregate of interest expense, including amortization of debt issuance costs, and an allocation of rental charges to approximate equivalent interest.
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|2 |  | Included as a deduction from income before income taxes and as an addition to interest expense in 2005 is accelerated amortization
of debt issuance costs in the amount of $5.0 million. Also included as a deduction from income before taxes in 2005, are losses on leased properties of $1.2 million. Excluding this amortization and these losses, the ratio of earnings to fixed
charges would have been 27.7 for the year ended December 31, 2005.
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|3 |  | Included as a deduction from income before income taxes in 2006 are restructuring costs of $26.3 million. Excluding these costs,
the ratio of earnings to fixed charges would have been 32.8 for the year ended December 31, 2006.
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|4 |  | Included as a deduction from income before income taxes in 2007 are restructuring costs of $5.2 million. Excluding these costs,
the ratio of earnings to fixed charges would have been 17.9 for the year ended December 31, 2007.
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