| Year | Total | vs prev |
|---|---|---|
| 2005 | 0 | −100.0% |
| 2004 | 23 | −94.4% |
| 2003 | 411 | +6.2% |
| 2002 | 387 | −7.2% |
| 2001 | 417 | −33.5% |
| 2000 | 627 | −3.8% |
| 1999 | 652 | −18.4% |
| 1998 | 799 | −15.5% |
| 1997 | 946 | +21.0% |
| 1996 | 782 | +0.9% |
| 1995 | 775 | −24.0% |
| 1994 | 1,020 | −32.5% |
| 1993 | 1,510 | −5.6% |
| 1992 | 1,599 | −5.2% |
| 1991 | 1,686 | — |