| Rok | Maximální | Minimální | Průměr |
|---|---|---|---|
| 2004 | 16.261 | 13.639 | 15.200 |
| 2005 | 15.116 | 13.558 | 14.387 |
| 2006 | 14.865 | 13.492 | 14.214 |
| 2007 | 14.191 | 12.269 | 13.459 |
| 2008 | 13.453 | 10.682 | 12.047 |
| 2009 | 15.291 | 12.043 | 13.049 |
| 2010 | 15.325 | 12.947 | 14.011 |
| 2011 | 15.417 | 13.234 | 14.063 |
| 2012 | 15.718 | 15.199 | 15.432 |