| Year | Total | vs prev |
|---|---|---|
| 2007 | 0 | −100.0% |
| 2006 | 39 | −85.7% |
| 2005 | 272 | +1713.3% |
| 2004 | 15 | −94.3% |
| 2003 | 264 | −43.7% |
| 2002 | 469 | +50.3% |
| 2001 | 312 | −20.0% |
| 2000 | 390 | +9.6% |
| 1999 | 356 | +77.1% |
| 1998 | 201 | +6.3% |
| 1997 | 189 | −36.4% |
| 1996 | 297 | −32.7% |
| 1995 | 441 | −2.6% |
| 1994 | 453 | +45.7% |
| 1993 | 311 | −5.2% |
| 1992 | 328 | −14.8% |
| 1991 | 385 | — |