| Year | Count |
|---|---|
| 1938 | 6 |
| 1939 | 11 |
| 1940 | 40 |
| 1941 | 5 |
| 1942 | 18 |
| 1943 | 13 |
| 1944 | 31 |
| 1945 | 54 |
| 1946 | 61 |
| 1947 | 133 |
| 1948 | 156 |
| 1949 | 80 |
| 1950 | 109 |
| 1951 | 100 |
| 1952 | 51 |
| 1953 | 89 |
| 1954 | 102 |
| 1955 | 160 |
| 1956 | 145 |
| 1957 | 227 |
| 1958 | 148 |
| 1959 | 189 |
| 1960 | 156 |
| 1961 | 141 |
| 1962 | 152 |
| 1963 | 172 |
| 1964 | 141 |
| 1965 | 111 |
| 1966 | 206 |
| 1967 | 135 |
| 1968 | 207 |
| 1969 | 142 |
| 1970 | 116 |
| 1971 | 77 |
| 1972 | 87 |
| 1973 | 59 |
| 1974 | 25 |
| 1975 | 48 |
| 1976 | 13 |
| 1977 | 25 |
| 1978 | 26 |
| 1979 | 24 |
| 1980 | 10 |
| 1982 | 5 |
| 1985 | 5 |
| 1988 | 5 |