| Year | Count |
|---|---|
| 1927 | 10 |
| 1928 | 12 |
| 1930 | 16 |
| 1931 | 14 |
| 1932 | 14 |
| 1933 | 22 |
| 1934 | 14 |
| 1935 | 30 |
| 1936 | 11 |
| 1937 | 8 |
| 1938 | 11 |
| 1939 | 13 |
| 1940 | 9 |
| 1941 | 11 |
| 1946 | 10 |
| 1950 | 5 |
| 1951 | 6 |
| 1952 | 27 |
| 1953 | 6 |
| 1954 | 12 |
| 1955 | 20 |
| 1956 | 25 |
| 1957 | 9 |
| 1958 | 20 |
| 1959 | 16 |
| 1960 | 17 |
| 1961 | 18 |
| 1962 | 10 |
| 1963 | 6 |
| 1964 | 15 |
| 1966 | 19 |
| 1967 | 6 |
| 1968 | 7 |
| 1969 | 18 |
| 1970 | 34 |
| 1971 | 46 |
| 1972 | 29 |
| 1973 | 11 |
| 1974 | 12 |
| 1975 | 5 |