Exhibit 12.1



RATIO OF EARNINGS TO FIXED
CHARGES

The ratio of earnings to fixed charges for the periods shown
has been computed by dividing earnings available for fixed charges (income from
continuing operations before income taxes plus fixed charges including
capitalized interest) by fixed charges (interest expense including capitalized
interest). Interest expense includes the portion of operating rental expense,
which we believe is representative of the interest component of rental expense.

|                                                               |  |                          |                                   |  |      |   |         |      |  |      |        |      |   |        |  |   |         |  
|-------------------------------------------------------------- |  | ------------------------ | --------------------------------- |  | ---- | - | ------- | ---- |  | ---- | ------ | ---- | - | ------ |  | - | ------- | -
|                                                               |  | Years Ended December 31, |                                  
|                                                               |  | 2004                     |                                   |  | 2003 |   |         | 2002 |  | 2001 |        | 2000 |  
|                                                               |  |                          | (In thousands, except ratio data)
|Income
  (loss) from continuing operations before income taxes |  | $                        | 193,222                           |  |      | $ | 126,683 |      |  | $    | 64,396 |      | $ | 22,642 |  | $ | (40,224 | )
|                                                               |  |                          |                                   |  |      |   |         |      |  |      |        |      |   |        |  |   |         |  
|Fixed Charges:                                                 |  |                          |                                  
|Interest
  expense (including capitalized interest)            |  |                          | 4,698                             |  |      |   | 5,506   |      |  |      | 7,700  |      |   | 15,767 |  |   | 17,932  |  
|Interest
  relating to rental expense (1)                      |  |                          | 7,747                             |  |      |   | 6,795   |      |  |      | 5,205  |      |   | 2,609  |  |   | 2,387   |  
|                                                               |  |                          |                                   |  |      |   |         |      |  |      |        |      |   |        |  |   |         |  
|Total Fixed Charges                                            |  |                          | 12,445                            |  |      |   | 12,301  |      |  |      | 12,905 |      |   | 18,376 |  |   | 20,319  |  
|                                                               |  |                          |                                   |  |      |   |         |      |  |      |        |      |   |        |  |   |         |  
|Earnings Available
  For Fixed Charges                         |  | $                        | 205,667                           |  |      | $ | 138,984 |      |  | $    | 77,301 |      | $ | 41,018 |  | $ | (19,905 | )
|                                                               |  |                          |                                   |  |      |   |         |      |  |      |        |      |   |        |  |   |         |  
|Ratio
  Of Earnings To Fixed Charges (2)                       |  |                          | 16.53                             |  |      |   | 11.30   |      |  |      | 5.99   |      |   | 2.23   |  |   |        |  



---

|(1) | The representative interest portion of rental expense was deemed to be one-third of all rental expense.                                                                      
|--- | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|(2) | Earnings were not sufficient to cover fixed charges during the year ended December 31, 2000 by $40.2 million; all other periods had sufficient income to cover fixed charges.