| Year | Count |
|---|---|
| 1941 | 7 |
| 1942 | 6 |
| 1943 | 12 |
| 1944 | 15 |
| 1945 | 13 |
| 1946 | 19 |
| 1947 | 26 |
| 1948 | 16 |
| 1949 | 10 |
| 1950 | 28 |
| 1951 | 20 |
| 1952 | 29 |
| 1953 | 23 |
| 1954 | 32 |
| 1955 | 45 |
| 1956 | 42 |
| 1957 | 104 |
| 1958 | 90 |
| 1959 | 92 |
| 1960 | 100 |
| 1961 | 62 |
| 1963 | 49 |
| 1964 | 47 |
| 1965 | 33 |
| 1966 | 36 |
| 1967 | 36 |
| 1968 | 34 |
| 1969 | 47 |
| 1970 | 47 |
| 1971 | 31 |
| 1972 | 25 |
| 1973 | 28 |
| 1974 | 14 |
| 1975 | 19 |
| 1976 | 22 |
| 1977 | 36 |
| 1978 | 40 |
| 1979 | 34 |
| 1980 | 36 |
| 1981 | 7 |
| 1982 | 14 |
| 1983 | 6 |
| 1984 | 16 |
| 1985 | 10 |
| 1986 | 8 |
| 1987 | 6 |
| 1988 | 8 |
| 1991 | 5 |