| Year | Count |
|---|---|
| 1934 | 8 |
| 1935 | 8 |
| 1936 | 8 |
| 1937 | 9 |
| 1938 | 12 |
| 1939 | 11 |
| 1940 | 9 |
| 1941 | 19 |
| 1942 | 24 |
| 1943 | 24 |
| 1944 | 20 |
| 1945 | 23 |
| 1946 | 41 |
| 1947 | 44 |
| 1948 | 35 |
| 1949 | 45 |
| 1950 | 32 |
| 1951 | 64 |
| 1952 | 52 |
| 1953 | 52 |
| 1954 | 47 |
| 1955 | 70 |
| 1956 | 44 |
| 1957 | 132 |
| 1958 | 98 |
| 1959 | 130 |
| 1960 | 116 |
| 1961 | 86 |
| 1963 | 35 |
| 1964 | 27 |
| 1965 | 25 |
| 1966 | 23 |
| 1967 | 17 |
| 1968 | 10 |
| 1969 | 10 |
| 1970 | 8 |
| 1971 | 5 |
| 1973 | 5 |