Exhibit 11

STATEMENT OF COMPUTATION OF PER SHARE EARNINGS

The following computations set forth the calculation of basic and
diluted net income per common share and common shares equivalents for the six-month and three-month periods ended June 30, 2006 and 2005:



|                                                                                    |  |                           |            |                             |   |            |  |      |            |  |   |           
|----------------------------------------------------------------------------------- |  | ------------------------- | ---------- | --------------------------- | - | ---------- |  | ---- | ---------- |  | - | ----------
|                                                                                    |  | Six Months Ended June 30, |            | Three Months Ended June 30,
|                                                                                    |  | 2006                      |            | 2005                        |   | 2006       |  | 2005
|Net income                                                                          |  | $                         | 45,645,890 |                             | $ | 50,125,505 |  | $    | 25,508,448 |  | $ | 28,555,161
|                                                                                    |  |                           |            |                             |   |            |  |      |            |  |   |           
|Weighted average number of common shares outstanding                                |  |                           | 80,315,256 |                             |   | 80,124,054 |  |      | 80,325,375 |  |   | 80,082,617
|                                                                                    |  |                           |            |                             |   |            |  |      |            |  |   |           
|Net income per common share - Basic                                                 |  | $                         | 0.57       |                             | $ | 0.63       |  | $    | 0.32       |  | $ | 0.36      
|                                                                                    |  |                           |            |                             |   |            |  |      |            |  |   |           
|                                                                                    |  |                          
|                                                                                    |  | Six Months Ended June 30, |            | Three Months Ended June 30,
|                                                                                    |  | 2006                      |            | 2005                        |   | 2006       |  | 2005
|Net income                                                                          |  | $                         | 45,645,890 |                             | $ | 50,125,505 |  | $    | 25,508,448 |  | $ | 28,555,161
|                                                                                    |  |                           |            |                             |   |            |  |      |            |  |   |           
|Weighted average number of common shares outstanding                                |  |                           | 80,315,256 |                             |   | 80,124,054 |  |      | 80,325,375 |  |   | 80,082,617
|Common share equivalents resulting from:                                            |  |                           |            |                             |   |            |  |      |            |  |   |           
|Dilutive stock options and restricted stock awards                                  |  |                           | 816,727    |                             |   | 485,297    |  |      | 853,835    |  |   | 455,995   
|                                                                                    |  |                           |            |                             |   |            |  |      |            |  |   |           
|Adjusted weighted average number of common and common equivalent shares outstanding |  |                           | 81,131,983 |                             |   | 80,609,351 |  |      | 81,179,210 |  |   | 80,538,612
|                                                                                    |  |                           |            |                             |   |            |  |      |            |  |   |           
|Net income per common share - Diluted                                               |  | $                         | 0.56       |                             | $ | 0.62       |  | $    | 0.31       |  | $ | 0.35      
|                                                                                    |  |                           |            |                             |   |            |  |      |            |  |   |