Exhibit 12.1

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES



|                                              |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       
|--------------------------------------------- |  | ------------------------------ | ------ | ------------------------ | - | ------------------------ |  | - | ------------------------ | - | ------------------------ | - | ------------------------ |  | - | ------- |  | - | ------
|(in thousands of U.S. dollars, except ratios) |  | Three MonthsEndedMarch 31,2010 |        | Year EndDecember 31,2009 |   | Year EndDecember 31,2008 |  |   | Year EndDecember 31,2007 |   | Year EndDecember 31,2006 |   | Year EndDecember 31,2005
|Earnings:                                     |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       
|Pre-tax income (loss)                         |  | $                              | 36,381 |                          | $ | 246,215                  |  | $ | (174,086                 | ) |                          | $ | 302,827                  |  | $ | 217,988 |  | $ | 10,477
|Fixed charges                                 |  |                                | 5,419  |                          |   | 23,260                   |  |   | 37,462                   |   |                          |   | 43,562                   |  |   | 14,503  |  |   | 23,235
|                                              |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       
|Total Earnings (Loss)                         |  | $                              | 41,800 |                          | $ | 269,475                  |  | $ | (136,624                 | ) |                          | $ | 346,389                  |  | $ | 232,491 |  | $ | 33,712
|                                              |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       
|Fixed Charges:                                |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       
|Interest and amortization on indebtedness     |  | $                              | 4,954  |                          | $ | 21,453                   |  | $ | 36,143                   |   |                          | $ | 42,702                   |  | $ | 13,832  |  | $ | 22,764
|Rental expense at 33.3% (1)                   |  |                                | 465    |                          |   | 1,807                    |  |   | 1,319                    |   |                          |   | 860                      |  |   | 671     |  |   | 471   
|                                              |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       
|Total Fixed Charges                           |  | $                              | 5,419  |                          | $ | 23,260                   |  | $ | 37,462                   |   |                          | $ | 43,562                   |  | $ | 14,503  |  | $ | 23,235
|                                              |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       
|Ratio of Earnings to Fixed Charges            |  |                                | 7.7    |                          |   | 11.6                     |  |   | (3.7                     | ) |                          |   | 8.0                      |  |   | 16.0    |  |   | 1.5   
|                                              |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       
|Deficiency                                    |  |                                | N/A    |                          |   | N/A                      |  | $ | 174,086                  |   |                          |   | N/A                      |  |   | N/A     |  |   | N/A   
|                                              |  |                                |        |                          |   |                          |  |   |                          |   |                          |   |                          |  |   |         |  |   |       



|(1) | 33.3% represents a reasonable approximation of the interest factor
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