| Year | Total | vs prev |
|---|---|---|
| 2008 | 0 | −100.0% |
| 2007 | 23 | −96.2% |
| 2006 | 610 | −33.7% |
| 2005 | 920 | +52.3% |
| 2004 | 604 | −34.5% |
| 2003 | 922 | −31.3% |
| 2002 | 1,342 | +47.1% |
| 2001 | 912 | +4.0% |
| 2000 | 877 | +2.2% |
| 1999 | 858 | +13.0% |
| 1998 | 759 | −23.9% |
| 1997 | 998 | −0.9% |
| 1996 | 1,007 | +0.8% |
| 1995 | 999 | −22.3% |
| 1994 | 1,286 | +21.3% |
| 1993 | 1,060 | +16.5% |
| 1992 | 910 | −17.3% |
| 1991 | 1,101 | — |