| Year | Count |
|---|---|
| 1971 | 15 |
| 1972 | 7 |
| 1974 | 16 |
| 1975 | 17 |
| 1977 | 12 |
| 1978 | 10 |
| 1979 | 61 |
| 1980 | 22 |
| 1981 | 17 |
| 1982 | 41 |
| 1983 | 34 |
| 1984 | 23 |
| 1985 | 40 |
| 1986 | 66 |
| 1987 | 73 |
| 1988 | 48 |
| 1989 | 54 |
| 1990 | 45 |
| 1991 | 89 |
| 1992 | 82 |
| 1993 | 77 |
| 1994 | 60 |
| 1995 | 110 |
| 1996 | 124 |
| 1997 | 121 |
| 1998 | 127 |
| 1999 | 117 |
| 2000 | 112 |
| 2001 | 131 |
| 2002 | 103 |
| 2003 | 134 |
| 2004 | 129 |
| 2005 | 125 |
| 2006 | 134 |
| 2007 | 155 |
| 2008 | 195 |
| 2009 | 99 |
| 2010 | 154 |
| 2011 | 107 |
| 2012 | 101 |
| 2013 | 178 |
| 2014 | 186 |
| 2015 | 119 |
| 2016 | 142 |
| 2017 | 102 |
| 2018 | 92 |
| 2019 | 55 |
| 2020 | 94 |
| 2021 | 76 |
| 2022 | 89 |
| 2023 | 70 |
| 2024 | 57 |