| Year | Count |
|---|---|
| 1936 | 5 |
| 1937 | 8 |
| 1938 | 7 |
| 1939 | 5 |
| 1940 | 6 |
| 1941 | 9 |
| 1942 | 19 |
| 1943 | 13 |
| 1944 | 10 |
| 1945 | 21 |
| 1946 | 21 |
| 1947 | 18 |
| 1948 | 17 |
| 1949 | 27 |
| 1950 | 22 |
| 1951 | 20 |
| 1952 | 18 |
| 1953 | 23 |
| 1954 | 21 |
| 1955 | 20 |
| 1956 | 7 |
| 1957 | 36 |
| 1958 | 20 |
| 1959 | 38 |
| 1960 | 38 |
| 1961 | 28 |
| 1962 | 9 |
| 1963 | 15 |
| 1964 | 12 |
| 1965 | 33 |
| 1966 | 14 |
| 1967 | 8 |
| 1970 | 10 |
| 1971 | 9 |
| 1972 | 9 |