| Year | Count |
|---|---|
| 1915 | 5 |
| 1920 | 6 |
| 1921 | 5 |
| 1923 | 12 |
| 1924 | 12 |
| 1928 | 14 |
| 1932 | 5 |
| 1933 | 10 |
| 1934 | 7 |
| 1935 | 5 |
| 1937 | 8 |
| 1938 | 6 |
| 1940 | 9 |
| 1941 | 7 |
| 1942 | 12 |
| 1945 | 5 |
| 1946 | 7 |
| 1947 | 7 |
| 1948 | 11 |
| 1949 | 9 |
| 1950 | 31 |
| 1951 | 17 |
| 1952 | 15 |
| 1953 | 5 |
| 1954 | 6 |
| 1956 | 10 |
| 1957 | 10 |
| 1958 | 16 |
| 1959 | 14 |
| 1960 | 32 |
| 1961 | 5 |
| 1963 | 6 |
| 1964 | 7 |
| 1965 | 10 |
| 1966 | 6 |
| 1967 | 6 |
| 1968 | 8 |
| 1969 | 7 |
| 1970 | 7 |
| 1972 | 9 |
| 1974 | 7 |
| 1975 | 6 |
| 1978 | 14 |
| 1979 | 10 |
| 1982 | 9 |
| 1983 | 6 |
| 1984 | 5 |
| 1985 | 9 |
| 1986 | 6 |
| 1989 | 5 |
| 1990 | 7 |
| 1991 | 7 |