| Year | |
|---|---|
| 1991 | 0.0 |
| 1992 | 0.0 |
| 1993 | 0.0 |
| 1994 | 0.0 |
| 1995 | 0.0 |
| 1996 | 0.0 |
| 1997 | 0.0 |
| 1998 | 0.0 |
| 1999 | 109.5 |
| 2000 | 116.0 |
| 2001 | 171.2 |
| 2002 | 271.6 |
| 2003 | 109.1 |
| 2004 | 297.9 |
| 2005 | 304.2 |
| 2006 | 282.8 |
| 2007 | 520.7 |
| 2008 | 206.5 |
| 2009 | 176.9 |
| 2010 | 202.5 |
| 2011 | 232.9 |
| 2012 | 283.1 |
| 2013 | 263.4 |
| 2014 | 224.9 |