| Year | Count |
|---|---|
| 1967 | 10 |
| 1968 | 10 |
| 1969 | 17 |
| 1970 | 23 |
| 1971 | 37 |
| 1972 | 53 |
| 1973 | 56 |
| 1974 | 44 |
| 1975 | 92 |
| 1976 | 122 |
| 1977 | 124 |
| 1978 | 132 |
| 1979 | 189 |
| 1980 | 185 |
| 1981 | 159 |
| 1982 | 159 |
| 1983 | 182 |
| 1984 | 177 |
| 1985 | 193 |
| 1986 | 165 |
| 1987 | 190 |
| 1988 | 205 |
| 1989 | 215 |
| 1990 | 201 |
| 1991 | 177 |
| 1992 | 275 |
| 1993 | 144 |
| 1994 | 81 |
| 1995 | 113 |
| 1996 | 76 |
| 1997 | 100 |
| 1998 | 86 |
| 1999 | 72 |
| 2000 | 78 |
| 2001 | 149 |
| 2002 | 122 |
| 2003 | 114 |
| 2004 | 137 |
| 2005 | 142 |
| 2006 | 148 |
| 2007 | 112 |
| 2008 | 177 |
| 2009 | 105 |
| 2010 | 95 |
| 2011 | 86 |
| 2012 | 99 |
| 2013 | 82 |
| 2014 | 94 |
| 2015 | 41 |
| 2016 | 36 |
| 2017 | 40 |
| 2018 | 46 |
| 2019 | 10 |
| 2020 | 18 |
| 2024 | 10 |