| Year | Total | vs prev |
|---|---|---|
| 2008 | 0 | −100.0% |
| 2007 | 3 | −99.5% |
| 2006 | 591 | −94.8% |
| 2005 | 11,415 | −19.9% |
| 2004 | 14,250 | −33.8% |
| 2003 | 21,541 | +1.3% |
| 2002 | 21,258 | −2.1% |
| 2001 | 21,720 | −6.7% |
| 2000 | 23,270 | −7.4% |
| 1999 | 25,121 | −23.0% |
| 1998 | 32,624 | −9.1% |
| 1997 | 35,880 | +16.3% |
| 1996 | 30,849 | +1.2% |
| 1995 | 30,469 | −17.7% |
| 1994 | 37,006 | +12.1% |
| 1993 | 33,017 | +5.6% |
| 1992 | 31,260 | +15.5% |
| 1991 | 27,066 | — |
