| Year | Count |
|---|---|
| 1940 | 7 |
| 1941 | 9 |
| 1942 | 9 |
| 1943 | 21 |
| 1944 | 15 |
| 1945 | 17 |
| 1946 | 32 |
| 1947 | 28 |
| 1948 | 29 |
| 1949 | 39 |
| 1950 | 48 |
| 1951 | 60 |
| 1952 | 49 |
| 1953 | 45 |
| 1954 | 60 |
| 1955 | 46 |
| 1956 | 29 |
| 1957 | 58 |
| 1958 | 76 |
| 1959 | 76 |
| 1960 | 66 |
| 1961 | 56 |
| 1963 | 17 |
| 1964 | 14 |
| 1965 | 6 |
| 1966 | 7 |
| 1968 | 11 |
| 1969 | 11 |
| 1970 | 16 |
| 1971 | 10 |
| 1972 | 9 |
| 1973 | 11 |
| 1974 | 10 |
| 1975 | 6 |
| 1977 | 10 |
| 1990 | 5 |
| 1991 | 6 |
| 1994 | 5 |