Exhibit 12.1



Ratio of Earnings to Fixed Charges



|                                                                        |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |   |         |   |  |   |          |  
|----------------------------------------------------------------------- |  | ----------------------------- | ------- | - | ------------------------ | - | ------- |  | ---- | ------- |  | ---- | ------ |  | - | ------- | - |  | - | -------- | -
|                                                                        |  | Six months ended June
30,2005 |         |   | Years ended December 31, |  
|                                                                        |  |                               | 2004    |   | 2003                     |   | 2002    |  | 2001 |         |  | 2000 |       
|                                                                        |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |   |         |   |  |   |          |  
|(in thousands, except ratios)                                           |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |  
|                                                                        |  |                               |         |   |                          |  
|Income (loss) before income taxes and extraordinary item                |  | $                             | 107,818 | 3 |                          | $ | 174,039 |  | $    | 87,716  |  | $    | 36,087 |  | $ | (98,662 | ) |  | $ | (164,151 | )
|Add fixed charges                                                       |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |   |         |   |  |   |          |  
|Interest expense                                                        |  |                               | 6,812   | 3 |                          |   | 3,828   |  |      | 9,765   |  |      | 15,364 |  |   | 17,231  |   |  |   | 15,828   |  
|Interest portion of rent expense                                        |  |                               | 3,265   |   |                          |   | 6,185   |  |      | 6,113   |  |      | 6,235  |  |   | 7,005   |   |  |   | 4,935    |  
|                                                                        |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |   |         |   |  |   |          |  
|Income (loss) before income taxes, extraordinary item and fixed charges |  | $                             | 117,895 |   |                          | $ | 184,082 |  | $    | 103,594 |  | $    | 57,686 |  | $ | (74,426 | ) |  | $ | (143,388 | )
|                                                                        |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |   |         |   |  |   |          |  
|Fixed charges                                                           |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |   |         |   |  |   |          |  
|Interest expense                                                        |  | $                             | 6,812   | 3 |                          | $ | 3,828   |  | $    | 9,765   |  | $    | 15,364 |  | $ | 17,231  |   |  | $ | 15,828   |  
|Interest portion of rent expense                                        |  |                               | 3,265   |   |                          |   | 6,185   |  |      | 6,113   |  |      | 6,235  |  |   | 7,005   |   |  |   | 4,935    |  
|                                                                        |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |   |         |   |  |   |          |  
|Fixed charges                                                           |  | $                             | 10,077  | 3 |                          | $ | 10,013  |  | $    | 15,878  |  | $    | 21,599 |  | $ | 24,236  |   |  | $ | 20,763   |  
|                                                                        |  |                               |         |   |                          |   |         |  |      |         |  |      |        |  |   |         |   |  |   |          |  
|Ratio of earnings to fixed charges 1                                    |  |                               | 11.7    | 3 |                          |   | 18.4    |  |      | 6.5     |  |      | 2.7    |  |   |        |   |  |   |         |  
|Deficiency of earnings to fixed charges 2                               |  |                               |        |   |                          |   |        |  |      |        |  |      |       |  | $ | (98,662 | ) |  | $ | (164,151 | )
|                                                                        | 

|  |  |                                                                                                                                                                                                                                                                                                                          
|- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|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.                   
|2 |  | Due to net losses incurred in 2001 and 2000, the ratio of earnings to fixed charges in those years was less than 1:1. We would have had to generate additional earnings in the amounts indicated in the
table to have achieved a ratio of 1:1.                                                                           
|3 |  | 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. Excluding this
amortization, the ratio of earnings to fixed charges would have been 23.4 for the six months ended June 30, 2005.