| Year | Count |
|---|---|
| 1938 | 8 |
| 1939 | 7 |
| 1941 | 9 |
| 1942 | 11 |
| 1943 | 9 |
| 1944 | 13 |
| 1945 | 11 |
| 1946 | 17 |
| 1947 | 13 |
| 1948 | 12 |
| 1949 | 12 |
| 1950 | 8 |
| 1951 | 15 |
| 1952 | 13 |
| 1953 | 20 |
| 1954 | 23 |
| 1955 | 18 |
| 1956 | 23 |
| 1957 | 64 |
| 1958 | 58 |
| 1959 | 46 |
| 1960 | 78 |
| 1961 | 64 |
| 1963 | 41 |
| 1964 | 49 |
| 1965 | 27 |
| 1966 | 23 |
| 1967 | 14 |
| 1968 | 18 |
| 1969 | 25 |
| 1970 | 17 |
| 1971 | 28 |
| 1972 | 20 |
| 1973 | 11 |
| 1974 | 8 |
| 1975 | 8 |
| 1976 | 8 |
| 1977 | 16 |
| 1978 | 14 |
| 1979 | 10 |
| 1981 | 7 |
| 1983 | 5 |
| 1987 | 5 |
| 1991 | 5 |
| 1992 | 5 |