|                                                        |                           |                                       |                                       |                                       |                                       |                                       | **Exhibit 12** |
|-------------------------------------------------------------|--------------------------------|--------------------------------------------|--------------------------------------------|--------------------------------------------|--------------------------------------------|--------------------------------------------|----------------|
| **Computation of Ratio of Earnings to Fixed Charges**       |                           |                                       |                                       |                                       |                                       |
| (Dollars in thousands)                                      |                           |                                       |                                       |                                       |                                       |                                       |
|                                                        |                           |                                       |                                       |                                       |                                       |                                       |           |
|                                                        |                           |                                       | For the year ended December 31,            |
|                                                        |                           |                                       | 2006                                       | 2005                                       | 2004                                       | 2003                                       | 2002           |
|                                                        |                           |                                       |                                       |                                       |                                       |                                       |           |
| Earnings before income taxes                                | $    896,348                   | $    799,425                               | $    526,991                               | $       393,064                            | $       225,741                            |
| Fixed charges                                               |                           |       62,546 |       68,472 |       20,649 |       20,865 |       18,501 |
| Earnings before income taxes and fixed charges              | $    958,894                   | $    867,897                               | $    547,640                               | $       413,929                            | $       244,242                            |
|                                                        |                           |                                       |                                       |                                       |                                       |                                       |           |
|                                                        |                           |                                       |                                       |                                       |                                       |                                       |           |
| Fixed charges:                                              |                           |                                       |                                       |                                       |                                       |                                       |
| Interest expense                                            |                           | $      52,446                              | $      58,414                              | $      14,301                              | $         15,051                           | $         13,446                           |
| Portion of rental expense representative of interest factor |     10,100 |     10,058             |       6,348  |      5,814        |       5,055  |
| Total fixed charges                                         |                           | $      62,546                              | $      68,472                              | $      20,649                              | $         20,865                           | $         18,501                           |
|                                                        |                           |                                       |                                       |                                       |                                       |                                       |           |
| Ratio of earnings to fixed charges                          | 15.3                           | 12.7                                       | 26.5                                       | 19.8                                       | 13.2                                       |
|                                                        |                           |                                       |                                       |                                       |                                       |                                       |           |
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