| Year | Count |
|---|---|
| 1938 | 5 |
| 1940 | 15 |
| 1941 | 13 |
| 1942 | 27 |
| 1943 | 23 |
| 1944 | 26 |
| 1945 | 39 |
| 1946 | 48 |
| 1947 | 50 |
| 1948 | 29 |
| 1949 | 16 |
| 1950 | 13 |
| 1951 | 17 |
| 1952 | 8 |
| 1953 | 8 |
| 1954 | 8 |
| 1955 | 6 |
| 1956 | 9 |
| 1957 | 30 |
| 1958 | 42 |
| 1959 | 70 |
| 1960 | 62 |
| 1961 | 84 |
| 1963 | 34 |
| 1964 | 25 |
| 1965 | 27 |
| 1966 | 29 |
| 1967 | 27 |
| 1968 | 19 |
| 1969 | 18 |
| 1970 | 12 |
| 1971 | 6 |
| 1974 | 5 |
| 1975 | 5 |
| 1978 | 10 |