| Year | Total | vs prev |
|---|---|---|
| 2018 | 0 | −100.0% |
| 2017 | 3 | −99.2% |
| 2016 | 392 | −56.3% |
| 2015 | 897 | +31.1% |
| 2014 | 684 | +8.7% |
| 2013 | 629 | +3.8% |
| 2012 | 606 | +39.3% |
| 2011 | 435 | +29.9% |
| 2010 | 335 | +30.9% |
| 2009 | 256 | −18.2% |
| 2008 | 313 | +201.0% |
| 2007 | 104 | −11.9% |
| 2006 | 118 | −22.9% |
| 2005 | 153 | −48.3% |
| 2004 | 296 | −11.4% |
| 2003 | 334 | +11.3% |
| 2002 | 300 | +24.0% |
| 2001 | 242 | −32.2% |
| 2000 | 357 | −21.7% |
| 1997 | 456 | — |