| Year | Count |
|---|---|
| 1950 | 7 |
| 1952 | 8 |
| 1954 | 6 |
| 1955 | 11 |
| 1956 | 13 |
| 1957 | 9 |
| 1958 | 9 |
| 1959 | 6 |
| 1960 | 9 |
| 1961 | 19 |
| 1967 | 9 |
| 1968 | 7 |
| 1969 | 17 |
| 1970 | 14 |
| 1971 | 11 |
| 1972 | 19 |
| 1973 | 35 |
| 1974 | 52 |
| 1975 | 42 |
| 1976 | 33 |
| 1977 | 23 |
| 1978 | 22 |
| 1979 | 47 |
| 1980 | 54 |
| 1981 | 45 |
| 1982 | 36 |
| 1983 | 37 |
| 1984 | 25 |
| 1985 | 45 |
| 1986 | 20 |
| 1987 | 21 |
| 1988 | 13 |
| 1989 | 8 |
| 1991 | 19 |
| 1992 | 17 |
| 1994 | 19 |
| 1995 | 24 |
| 1996 | 5 |
| 1997 | 9 |
| 2000 | 14 |
| 2005 | 18 |
| 2020 | 5 |