| Year | Count |
|---|---|
| 1957 | 6 |
| 1958 | 13 |
| 1959 | 6 |
| 1960 | 51 |
| 1961 | 102 |
| 1962 | 81 |
| 1963 | 77 |
| 1964 | 77 |
| 1965 | 92 |
| 1966 | 93 |
| 1967 | 98 |
| 1968 | 180 |
| 1969 | 196 |
| 1970 | 232 |
| 1971 | 259 |
| 1972 | 164 |
| 1973 | 165 |
| 1974 | 199 |
| 1975 | 162 |
| 1976 | 129 |
| 1977 | 136 |
| 1978 | 96 |
| 1979 | 179 |
| 1980 | 215 |
| 1981 | 184 |
| 1982 | 168 |
| 1983 | 160 |
| 1984 | 126 |
| 1985 | 135 |
| 1986 | 56 |
| 1987 | 54 |
| 1988 | 84 |
| 1989 | 97 |
| 1990 | 74 |
| 1991 | 44 |
| 1992 | 31 |
| 1993 | 21 |
| 1995 | 10 |
| 1996 | 6 |
| 1997 | 12 |
| 1998 | 21 |
| 2002 | 5 |
| 2004 | 22 |
| 2017 | 5 |
| 2019 | 6 |
| 2020 | 12 |