| Year | Total | vs prev |
|---|---|---|
| 2013 | 0 | −100.0% |
| 2012 | 7 | −81.1% |
| 2011 | 37 | +3600.0% |
| 2010 | 1 | −98.0% |
| 2009 | 50 | −16.7% |
| 2008 | 60 | −32.6% |
| 2007 | 89 | −21.2% |
| 2006 | 113 | −35.4% |
| 2005 | 175 | −34.2% |
| 2004 | 266 | −33.0% |
| 2003 | 397 | −46.1% |
| 2002 | 736 | −29.3% |
| 2001 | 1,041 | +78.9% |
| 2000 | 582 | +15.0% |
| 1999 | 506 | +37.9% |
| 1998 | 367 | — |