| Year | Count |
|---|---|
| 1975 | 5 |
| 1976 | 5 |
| 1983 | 12 |
| 1984 | 10 |
| 1985 | 13 |
| 1986 | 18 |
| 1987 | 13 |
| 1988 | 21 |
| 1989 | 46 |
| 1990 | 55 |
| 1991 | 96 |
| 1992 | 101 |
| 1993 | 82 |
| 1994 | 118 |
| 1995 | 92 |
| 1996 | 54 |
| 1997 | 85 |
| 1998 | 18 |
| 1998 | 59 |
| 1999 | 43 |
| 2000 | 36 |
| 2001 | 42 |
| 2002 | 15 |
| 2003 | 16 |
| 2004 | 42 |
| 2005 | 29 |
| 2006 | 14 |
| 2007 | 29 |
| 2008 | 40 |
| 2009 | 53 |
| 2010 | 39 |
| 2011 | 28 |
| 2012 | 28 |
| 2013 | 7 |
| 2014 | 16 |
| 2015 | 28 |
| 2016 | 10 |
| 2017 | 26 |
| 2018 | 16 |
| 2019 | 12 |
| 2020 | 15 |
| 2021 | 12 |
| 2024 | 10 |