| Year | Total | vs prev |
|---|---|---|
| 2013 | 0 | −100.0% |
| 2012 | 12 | −85.0% |
| 2011 | 80 | +900.0% |
| 2010 | 8 | −97.9% |
| 2009 | 377 | −49.5% |
| 2008 | 747 | −36.4% |
| 2007 | 1,175 | +39.7% |
| 2006 | 841 | +22.1% |
| 2005 | 689 | −19.7% |
| 2004 | 858 | −9.9% |
| 2003 | 952 | +5.2% |
| 2002 | 905 | +17.5% |
| 2001 | 770 | +45.8% |
| 2000 | 528 | −23.1% |
| 1999 | 687 | +87.7% |
| 1998 | 366 | — |