| Year | Count |
|---|---|
| 1967 | 6 |
| 1969 | 24 |
| 1970 | 7 |
| 1971 | 30 |
| 1972 | 30 |
| 1973 | 37 |
| 1974 | 45 |
| 1975 | 58 |
| 1976 | 73 |
| 1977 | 102 |
| 1978 | 120 |
| 1979 | 152 |
| 1980 | 100 |
| 1981 | 137 |
| 1982 | 94 |
| 1983 | 117 |
| 1984 | 110 |
| 1985 | 146 |
| 1986 | 141 |
| 1987 | 99 |
| 1988 | 98 |
| 1989 | 91 |
| 1990 | 131 |
| 1991 | 128 |
| 1992 | 130 |
| 1993 | 106 |
| 1994 | 119 |
| 1995 | 93 |
| 1996 | 136 |
| 1997 | 164 |
| 1998 | 134 |
| 1999 | 181 |
| 2000 | 109 |
| 2001 | 167 |
| 2002 | 96 |
| 2003 | 84 |
| 2004 | 114 |
| 2005 | 89 |
| 2006 | 84 |
| 2007 | 91 |
| 2008 | 72 |
| 2009 | 71 |
| 2010 | 39 |
| 2011 | 36 |
| 2012 | 17 |
| 2014 | 30 |
| 2015 | 8 |
| 2016 | 8 |
| 2017 | 5 |
| 2018 | 16 |
| 2019 | 13 |
| 2021 | 5 |
| 2022 | 17 |
| 2023 | 22 |
| 2024 | 5 |