| Year | Count |
|---|---|
| 1942 | 7 |
| 1943 | 5 |
| 1944 | 17 |
| 1945 | 19 |
| 1946 | 22 |
| 1947 | 17 |
| 1948 | 17 |
| 1949 | 20 |
| 1950 | 8 |
| 1951 | 11 |
| 1952 | 9 |
| 1953 | 16 |
| 1954 | 15 |
| 1955 | 24 |
| 1956 | 29 |
| 1957 | 120 |
| 1958 | 216 |
| 1959 | 198 |
| 1960 | 204 |
| 1961 | 150 |
| 1963 | 68 |
| 1964 | 54 |
| 1965 | 39 |
| 1966 | 23 |
| 1967 | 30 |
| 1968 | 18 |
| 1969 | 10 |
| 1970 | 15 |
| 1971 | 8 |
| 1972 | 6 |
| 1973 | 6 |