| Year | Count |
|---|---|
| 1974 | 5 |
| 1977 | 6 |
| 1978 | 10 |
| 1979 | 13 |
| 1980 | 5 |
| 1981 | 6 |
| 1982 | 5 |
| 1984 | 19 |
| 1985 | 12 |
| 1986 | 40 |
| 1987 | 51 |
| 1988 | 31 |
| 1989 | 37 |
| 1990 | 83 |
| 1991 | 20 |
| 1992 | 43 |
| 1993 | 40 |
| 1994 | 20 |
| 1995 | 29 |
| 1996 | 132 |
| 1997 | 212 |
| 1998 | 157 |
| 1999 | 156 |
| 2000 | 147 |
| 2001 | 115 |
| 2002 | 160 |
| 2003 | 92 |
| 2004 | 143 |
| 2005 | 128 |
| 2006 | 183 |
| 2007 | 270 |
| 2008 | 306 |
| 2009 | 222 |
| 2010 | 180 |
| 2011 | 170 |
| 2012 | 111 |
| 2013 | 143 |
| 2014 | 123 |
| 2015 | 70 |
| 2016 | 31 |
| 2017 | 16 |
| 2018 | 12 |
| 2020 | 5 |
| 2021 | 57 |
| 2022 | 84 |
| 2023 | 102 |
| 2024 | 82 |