| Year | Count |
|---|---|
| 1963 | 5 |
| 1965 | 12 |
| 1966 | 14 |
| 1967 | 9 |
| 1968 | 13 |
| 1969 | 40 |
| 1970 | 44 |
| 1971 | 35 |
| 1972 | 34 |
| 1973 | 43 |
| 1974 | 33 |
| 1975 | 57 |
| 1976 | 92 |
| 1977 | 158 |
| 1978 | 158 |
| 1979 | 132 |
| 1980 | 90 |
| 1981 | 65 |
| 1982 | 47 |
| 1983 | 42 |
| 1984 | 125 |
| 1985 | 164 |
| 1986 | 113 |
| 1987 | 128 |
| 1988 | 115 |
| 1989 | 83 |
| 1990 | 76 |
| 1991 | 78 |
| 1992 | 72 |
| 1993 | 61 |
| 1994 | 34 |
| 1995 | 29 |
| 1996 | 27 |
| 1997 | 23 |
| 1998 | 26 |
| 1999 | 21 |
| 2000 | 17 |
| 2001 | 7 |
| 2002 | 11 |
| 2003 | 25 |
| 2004 | 14 |
| 2006 | 5 |
| 2007 | 7 |
| 2008 | 9 |
| 2015 | 18 |
| 2017 | 15 |
| 2019 | 14 |
| 2020 | 10 |
| 2024 | 10 |