| Jahr | Maximum | Mittel | Minimum |
| 2012 | 3.32 | 3.10 | 2.87 |
| 2011 | 4.09 | 3.26 | 2.73 |
| 2010 | 4.53 | 3.47 | 2.73 |
| 2009 | 4.26 | 3.31 | 2.64 |
| 2008 | 4.29 | 3.36 | 2.60 |
| 2007 | 4.02 | 3.14 | 2.54 |
| 2006 | 3.98 | 3.04 | 2.29 |
| 2005 | 4.09 | 3.07 | 2.44 |
| 2004 | 4.03 | 3.17 | 2.51 |
| 2003 | 3.65 | 3.05 | 2.55 |
| 2002 | 4.36 | 3.49 | 2.73 |
| 2001 | 4.87 | 3.62 | 2.86 |
| 2000 | 4.59 | 3.54 | 2.88 |
| 1999 | 5.65 | 3.73 | 2.72 |
| 1998 | 3.73 | 3.21 | 2.59 |
| 1997 | 4.49 | 3.21 | 2.61 |
| 1996 | 3.95 | 3.08 | 2.45 |