Exhibit 12.1

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES AND RATIO OF EARNINGS TO COMBINED

FIXED CHARGES AND PREFERRED STOCK DIVIDENDS



|                                                                       |  |                         |        |   |      |   |         |      |  |   |        |   |  |      |         |   |  |   |         |  
|---------------------------------------------------------------------- |  | ----------------------- | ------ | - | ---- | - | ------- | ---- |  | - | ------ | - |  | ---- | ------- | - |  | - | ------- | -
|                                                                       |  | Year Ended December 31, |       
|                                                                       |  | 2005                    |        |   | 2006 |   |         | 2007 |  |   | 2008   |   |  | 2009 |        
|                                                                       |  | ($ in thousands)        |       
|Pre-tax income from continuing operations                              |  | $                       | 39,027 |   |      | $ | 101,136 |      |  | $ | 43,998 |   |  | $    | 168,434 |   |  | $ | 88,174  |  
|Fixed charges and preferred dividends                                  |  |                         | 3,465  |   |      |   | 11,761  |      |  |   | 14,677 |   |  |      | 21,853  |   |  |   | 35,696  |  
|Amortization of capitalized interest                                   |  |                         |       |   |      |   | 7       |      |  |   | 87     |   |  |      | 149     |   |  |   | 404     |  
|Interest capitalized                                                   |  |                         |       |   |      |   | (968    | )    |  |   | (1,622 | ) |  |      | (1,666  | ) |  |   | (4,576  | )
|Preferred dividends                                                    |  |                         |       |   |      |   |        |      |  |   |       |   |  |      |        |   |  |   |        |  
|                                                                       |  |                         |        |   |      |   |         |      |  |   |        |   |  |      |         |   |  |   |         |  
|Total adjusted earnings available for payment of fixed charges         |  | $                       | 42,492 |   |      | $ | 111,936 |      |  | $ | 57,140 |   |  | $    | 188,770 |   |  | $ | 119,698 |  
|                                                                       |  |                         |        |   |      |   |         |      |  |   |        |   |  |      |         |   |  |   |         |  
|                                                                       |  |                         |        |   |     
|Fixed charges and preferred dividends                                  |  |                         |        |   |      |   |         |      |  |   |        |   |  |      |         |   |  |   |         |  
|                                                                       |  |                         |        |   |     
|Interest expense                                                       |  | $                       | 1,999  |   |      | $ | 9,783   |      |  | $ | 12,119 |   |  | $    | 18,128  |   |  | $ | 28,143  |  
|Interest capitalized                                                   |  |                         |       |   |      |   | 968     |      |  |   | 1,622  |   |  |      | 1,666   |   |  |   | 4,576   |  
|Amortization of debt-related expenses                                  |  |                         | 1,175  |   |      |   | 556     |      |  |   | 482    |   |  |      | 1,590   |   |  |   | 2,504   |  
|Rental expense representative of interest factor                       |  |                         | 291    |   |      |   | 454     |      |  |   | 454    |   |  |      | 469     |   |  |   | 473     |  
|Preferred dividends                                                    |  |                         |       |   |      |   |        |      |  |   |       |   |  |      |        |   |  |   |        |  
|                                                                       |  |                         |        |   |      |   |         |      |  |   |        |   |  |      |         |   |  |   |         |  
|Total fixed charges and preferred dividends                            |  | $                       | 3,465  |   |      | $ | 11,761  |      |  | $ | 14,677 |   |  | $    | 21,853  |   |  | $ | 35,696  |  
|                                                                       |  |                         |        |   |      |   |         |      |  |   |        |   |  |      |         |   |  |   |         |  
|Ratio of earnings to fixed charges                                     |  |                         | 12.3   | x |      |   | 9.5     | x    |  |   | 3.9    | x |  |      | 8.6     | x |  |   | 3.4     | x
|Ratio of earnings to combined fixed charges and preferred dividends(1) |  |                         | 12.3   | x |      |   | 9.5     | x    |  |   | 3.9    | x |  |      | 8.6     | x |  |   | 3.4     | x



|(1) | The ratio of earnings to combined fixed charges and preferred dividends is the same as the ratio of earnings to fixed charges because no shares of preferred stock were
outstanding during those periods.
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