| Year | Total | vs prev |
|---|---|---|
| 2021 | 0 | −100.0% |
| 2020 | 23 | −97.2% |
| 2019 | 814 | −14.2% |
| 2018 | 949 | −22.4% |
| 2017 | 1,223 | −36.8% |
| 2016 | 1,936 | −30.0% |
| 2015 | 2,767 | — |
| 2014 | 0 | −100.0% |
| 2013 | 75 | +8.7% |
| 2012 | 69 | −2.8% |
| 2011 | 71 | −45.4% |
| 2010 | 130 | +23.8% |
| 2009 | 105 | +75.0% |
| 2008 | 60 | −38.1% |
| 2007 | 97 | −69.4% |
| 2006 | 317 | −31.5% |
| 2005 | 463 | −21.9% |
| 2004 | 593 | −51.7% |
| 2003 | 1,228 | −28.2% |
| 2002 | 1,710 | +882.8% |
| 2001 | 174 | — |