Zobrazení grafu: týden | měsíc | půl roku | rok | 5 let | 15 let
| Rok | Maximální | Minimální | Průměr |
|---|---|---|---|
| 1991 | 4.740 | 4.410 | 4.550 |
| 1992 | 4.830 | 4.157 | 4.557 |
| 1993 | 4.271 | 3.989 | 4.112 |
| 1994 | 4.199 | 3.991 | 4.078 |
| 1995 | 4.238 | 4.121 | 4.188 |
| 1996 | 4.281 | 4.055 | 4.205 |
| 1997 | 4.888 | 4.199 | 4.478 |
| 1998 | 4.808 | 3.784 | 4.276 |
| 1999 | 4.612 | 3.947 | 4.433 |
| 2000 | 4.519 | 4.249 | 4.388 |
| 2001 | 4.338 | 3.928 | 4.232 |
| 2002 | 4.347 | 3.939 | 4.104 |
| 2003 | 4.379 | 3.800 | 3.986 |
| 2004 | 4.003 | 3.678 | 3.812 |
| 2005 | 3.840 | 3.557 | 3.719 |
| 2006 | 3.665 | 3.338 | 3.524 |
| 2007 | 3.625 | 3.236 | 3.462 |
| 2008 | 3.346 | 2.662 | 3.041 |
| 2009 | 3.350 | 2.761 | 3.026 |
| 2010 | 3.342 | 2.985 | 3.160 |
| 2011 | 3.333 | 3.032 | 3.155 |
| 2012 | 3.481 | 3.217 | 3.363 |
| 2013 | 3.512 | 3.115 | 3.333 |
| 2014 | 3.419 | 2.892 | 3.297 |
| 2015 | 3.291 | 2.810 | 3.056 |
| 2016 | 3.030 | 2.786 | 2.909 |
| 2017 | 3.068 | 2.578 | 2.826 |
| 2018 | 2.680 | 2.586 | 2.636 |