| Year | Count |
|---|---|
| 1979 | 7 |
| 1980 | 7 |
| 1981 | 7 |
| 1983 | 20 |
| 1984 | 32 |
| 1985 | 8 |
| 1986 | 21 |
| 1987 | 39 |
| 1988 | 31 |
| 1989 | 41 |
| 1990 | 18 |
| 1991 | 71 |
| 1992 | 66 |
| 1993 | 91 |
| 1994 | 107 |
| 1995 | 118 |
| 1996 | 104 |
| 1997 | 81 |
| 1998 | 64 |
| 1999 | 77 |
| 2000 | 97 |
| 2001 | 67 |
| 2002 | 41 |
| 2003 | 50 |
| 2004 | 58 |
| 2005 | 108 |
| 2006 | 161 |
| 2007 | 96 |
| 2008 | 116 |
| 2009 | 94 |
| 2010 | 101 |
| 2011 | 68 |
| 2012 | 48 |
| 2013 | 22 |
| 2014 | 12 |
| 2015 | 42 |
| 2016 | 22 |
| 2017 | 10 |
| 2018 | 6 |
| 2020 | 15 |
| 2022 | 8 |
| 2024 | 6 |