| Year | Total | vs prev |
|---|---|---|
| 2013 | 0 | −100.0% |
| 2012 | 8 | −75.8% |
| 2011 | 33 | +560.0% |
| 2010 | 5 | −97.9% |
| 2009 | 236 | −32.8% |
| 2008 | 351 | −41.3% |
| 2007 | 598 | −8.1% |
| 2006 | 651 | +0.8% |
| 2005 | 646 | −10.8% |
| 2004 | 724 | −9.8% |
| 2003 | 803 | −18.9% |
| 2002 | 990 | +2.4% |
| 2001 | 967 | +52.5% |
| 2000 | 634 | −3.1% |
| 1999 | 654 | +77.7% |
| 1998 | 368 | — |