|                                                                           |   | December 31, |   |
|--------------------------------------------------------------------------------|--------|--------------|--------|
|                                                                           |   | 2010         |   |   | 2009 |   |   | 2008(1) |   |    | 2007(1) |   |   | 2006(1) |   |
| Earnings:                                                                      |   |         |   |   |   |   |   |   |   |   |   |   |    |   |   |   |   |   |   |   |
| Pretax income                                                                  |   | $            | 26,364 |   |   | $ | 29,256 |   |   | $ | (49,897 | ) |   | $ | (233,855 | ) |   | $ | (18,277 | ) |
| Fixed charges                                                                  |   |         | 44,084 |   |   |   | 54,752 |   |   |   | 52,147 |   |   |   | 45,365 |   |   |   | 21,417 |   |
| Amortization of capitalized interest                                           |   |         | 506    |   |   |   | 445 |   |   |   | 255 |   |   |   | 32 |   |   |   | —   |   |
| Capitalized interest                                                           |   |         | (2,626 | ) |   |   | (325 | ) |   |   | (5,946 | ) |   |   | (5,057 | ) |   |   | (990 | ) |
| Total earnings                                                                 |   | $            | 68,328 |   |   | $ | 84,128 |   |   | $ | (3,441 | ) |   | $ | (193,515 | ) |   | $ | 2,150 |   |
|                                                                           |   |         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Fixed charges:                                                                 |   |         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Interest expense                                                               |   | $            | 36,265 |   |   | $ | 47,724 |   |   | $ | 46,737 |   |   | $ | 35,923 |   |   | $ | 17,303 |   |
| Amortized premiums, discounts and capitalized expenses related to indebtedness |   |         | 7,798  |   |   |   | 7,001 |   |   |   | 5,367 |   |   |   | 9,140 |   |   |   | 3,418 |   |
| Estimated interest expense within rental expense                               |   |         | 21     |   |   |   | 27 |   |   |   | 43 |   |   |   | 302 |   |   |   | 696 |   |
| Total fixed charges                                                            |   | $            | 44,084 |   |   | $ | 54,752 |   |   | $ | 52,147 |   |   | $ | 45,365 |   |   | $ | 21,417 |   |
|                                                                           |   |         |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Ratio of earnings to fixed charges                                             |   |         | 1.55   |   |   |   | 1.54 |   |   |   | —   |   |   |   | —   |   |   |   | 0.10 |   |

| (1) | The amount of additional earnings needed to obtain a ratio of earnings to fixed charges of 1x was approximately $55.6 million, $238.9 million and $19.3 million for the years ended December 31, 2008, 2007 and 2006, respectively. |
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