| Year | Total | vs prev |
|---|---|---|
| 2010 | 0 | −100.0% |
| 2009 | 4 | −87.1% |
| 2008 | 31 | −70.5% |
| 2007 | 105 | −86.5% |
| 2006 | 777 | −61.2% |
| 2005 | 2,001 | +14.6% |
| 2004 | 1,746 | −3.5% |
| 2003 | 1,809 | −22.3% |
| 2002 | 2,329 | +788.9% |
| 2001 | 262 | +26100.0% |
| 1995 | 1 | −99.1% |
| 1994 | 115 | −21.8% |
| 1993 | 147 | −46.9% |
| 1992 | 277 | −12.1% |
| 1991 | 315 | — |