| Year | Count |
|---|---|
| 1947 | 6 |
| 1949 | 16 |
| 1950 | 15 |
| 1951 | 12 |
| 1952 | 20 |
| 1953 | 23 |
| 1954 | 32 |
| 1955 | 46 |
| 1956 | 40 |
| 1957 | 130 |
| 1958 | 88 |
| 1959 | 120 |
| 1960 | 98 |
| 1961 | 102 |
| 1963 | 56 |
| 1964 | 49 |
| 1965 | 37 |
| 1966 | 36 |
| 1967 | 27 |
| 1968 | 32 |
| 1969 | 23 |
| 1970 | 21 |
| 1971 | 24 |
| 1972 | 16 |
| 1973 | 24 |
| 1974 | 23 |
| 1975 | 18 |
| 1976 | 17 |
| 1977 | 36 |
| 1978 | 28 |
| 1979 | 28 |
| 1981 | 8 |
| 1982 | 6 |
| 1984 | 9 |
| 1985 | 10 |