| Year | Staff | Percentage |
| 2006 | 67 | 7.4 |
| 2007 | 135 | 14.9 |
| 2008 | 180 | 19.9 |
| 2009 | 251 | 27.7 |
| 2010 | 90 | 9.9 |
| 2011 | 183 | 20.2 |
| Total | 906 | 100.0 |