| Year | Total | vs prev |
|---|---|---|
| 2008 | 0 | −100.0% |
| 2007 | 292 | −95.6% |
| 2006 | 6,625 | +8.6% |
| 2005 | 6,102 | +6.9% |
| 2004 | 5,706 | +6.4% |
| 2003 | 5,364 | +23.3% |
| 2002 | 4,349 | −12.0% |
| 2001 | 4,941 | +7.3% |
| 2000 | 4,605 | −4.8% |
| 1999 | 4,835 | +22.8% |
| 1998 | 3,936 | −0.7% |
| 1997 | 3,964 | −2.4% |
| 1996 | 4,063 | +23.2% |
| 1995 | 3,299 | −16.4% |
| 1994 | 3,945 | +48.6% |
| 1993 | 2,654 | −15.9% |
| 1992 | 3,157 | +73.2% |
| 1991 | 1,823 | — |
