| Rok | Maximální | Minimální | Průměr |
|---|---|---|---|
| 2004 | 50.420 | 43.575 | 48.001 |
| 2005 | 43.898 | 41.440 | 42.775 |
| 2006 | 41.722 | 39.303 | 40.699 |
| 2007 | 41.334 | 37.255 | 39.647 |
| 2008 | 38.225 | 32.665 | 35.539 |
| 2009 | 41.645 | 35.551 | 37.398 |
| 2010 | 37.311 | 34.388 | 35.710 |
| 2011 | 37.298 | 33.956 | 34.819 |
| 2012 | 37.107 | 35.815 | 36.438 |