| Year | Count |
|---|---|
| 1958 | 7 |
| 1967 | 5 |
| 1970 | 5 |
| 1971 | 5 |
| 1972 | 10 |
| 1973 | 6 |
| 1974 | 25 |
| 1975 | 45 |
| 1976 | 33 |
| 1977 | 95 |
| 1978 | 21 |
| 1979 | 93 |
| 1980 | 94 |
| 1981 | 149 |
| 1982 | 164 |
| 1983 | 144 |
| 1984 | 137 |
| 1985 | 207 |
| 1986 | 200 |
| 1987 | 173 |
| 1988 | 205 |
| 1989 | 170 |
| 1990 | 188 |
| 1991 | 214 |
| 1992 | 233 |
| 1993 | 241 |
| 1994 | 331 |
| 1995 | 229 |
| 1996 | 157 |
| 1997 | 79 |
| 1998 | 81 |
| 1999 | 40 |
| 2000 | 20 |
| 2002 | 11 |
| 2004 | 15 |
| 2005 | 40 |
| 2007 | 11 |
| 2008 | 11 |
| 2009 | 17 |
| 2010 | 6 |
| 2011 | 6 |
| 2012 | 5 |
| 2013 | 7 |
| 2015 | 40 |
| 2016 | 36 |
| 2017 | 38 |
| 2018 | 24 |
| 2019 | 21 |
| 2020 | 18 |
| 2021 | 22 |
| 2022 | 36 |
| 2023 | 32 |
| 2024 | 14 |