| Year | Count |
|---|---|
| 1932 | 12 |
| 1933 | 26 |
| 1934 | 26 |
| 1935 | 29 |
| 1936 | 5 |
| 1937 | 12 |
| 1938 | 19 |
| 1939 | 20 |
| 1940 | 20 |
| 1941 | 24 |
| 1942 | 43 |
| 1943 | 23 |
| 1944 | 37 |
| 1945 | 16 |
| 1946 | 71 |
| 1947 | 81 |
| 1948 | 87 |
| 1949 | 95 |
| 1950 | 79 |
| 1951 | 123 |
| 1952 | 162 |
| 1953 | 752 |
| 1954 | 676 |
| 1955 | 629 |
| 1956 | 604 |
| 1957 | 619 |
| 1958 | 558 |
| 1959 | 487 |
| 1960 | 448 |
| 1961 | 417 |
| 1962 | 270 |
| 1963 | 295 |
| 1964 | 229 |
| 1965 | 157 |
| 1966 | 112 |
| 1967 | 102 |
| 1968 | 69 |
| 1969 | 76 |
| 1970 | 40 |
| 1971 | 9 |
| 1972 | 20 |
| 1975 | 6 |