| Year | Total | vs prev |
|---|---|---|
| 2009 | 0 | −100.0% |
| 2008 | 16 | −97.6% |
| 2007 | 669 | −90.6% |
| 2006 | 7,125 | −6.3% |
| 2005 | 7,604 | +7.4% |
| 2004 | 7,077 | +14.5% |
| 2003 | 6,179 | +3.5% |
| 2002 | 5,968 | −9.4% |
| 2001 | 6,587 | −2.7% |
| 2000 | 6,769 | +16.3% |
| 1999 | 5,822 | +0.2% |
| 1998 | 5,808 | +10.1% |
| 1997 | 5,275 | +7.9% |
| 1996 | 4,889 | +1.5% |
| 1995 | 4,816 | +6.5% |
| 1994 | 4,520 | +83.4% |
| 1993 | 2,464 | −6.7% |
| 1992 | 2,640 | +12.5% |
| 1991 | 2,347 | — |
