| Year | Count |
|---|---|
| 1948 | 5 |
| 1949 | 11 |
| 1950 | 7 |
| 1952 | 8 |
| 1953 | 16 |
| 1954 | 15 |
| 1955 | 8 |
| 1956 | 10 |
| 1958 | 5 |
| 1959 | 11 |
| 1960 | 9 |
| 1961 | 8 |
| 1962 | 6 |
| 1963 | 7 |
| 1965 | 11 |
| 1966 | 11 |
| 1967 | 6 |
| 1968 | 10 |
| 1969 | 13 |
| 1970 | 21 |
| 1971 | 24 |
| 1972 | 10 |
| 1973 | 24 |
| 1974 | 17 |
| 1975 | 23 |
| 1976 | 11 |
| 1977 | 15 |
| 1979 | 8 |
| 1980 | 7 |
| 1982 | 6 |
| 1985 | 5 |
| 1986 | 9 |
| 1989 | 5 |
| 1996 | 5 |
| 1999 | 5 |