| Year | Total | vs prev |
|---|---|---|
| 2019 | 0 | −100.0% |
| 2018 | 6 | −97.1% |
| 2017 | 210 | −95.3% |
| 2016 | 4,434 | −25.3% |
| 2015 | 5,938 | −6.5% |
| 2014 | 6,349 | −40.2% |
| 2013 | 10,610 | −24.4% |
| 2012 | 14,036 | −25.1% |
| 2011 | 18,741 | −36.5% |
| 2010 | 29,516 | −4.9% |
| 2009 | 31,023 | −2.9% |
| 2008 | 31,936 | −5.9% |
| 2007 | 33,941 | −19.9% |
| 2006 | 42,390 | −20.1% |
| 2005 | 53,080 | −18.8% |
| 2004 | 65,384 | −10.7% |
| 2003 | 73,220 | +34.0% |
| 2002 | 54,629 | +2.0% |
| 2001 | 53,534 | −11.5% |
| 2000 | 60,460 | −13.7% |
| 1999 | 70,084 | +1.9% |
| 1998 | 68,745 | −4.3% |
| 1997 | 71,850 | −17.5% |
| 1996 | 87,073 | −2.9% |
| 1995 | 89,679 | +10.5% |
| 1994 | 81,134 | +14.0% |
| 1993 | 71,157 | +5.7% |
| 1992 | 67,315 | +25.5% |
| 1991 | 53,618 | — |