| Year | Count |
|---|---|
| 1937 | 5 |
| 1939 | 7 |
| 1940 | 6 |
| 1941 | 12 |
| 1942 | 14 |
| 1943 | 13 |
| 1944 | 13 |
| 1945 | 15 |
| 1946 | 20 |
| 1947 | 22 |
| 1948 | 13 |
| 1949 | 15 |
| 1950 | 15 |
| 1951 | 22 |
| 1952 | 27 |
| 1953 | 32 |
| 1954 | 29 |
| 1955 | 41 |
| 1956 | 36 |
| 1957 | 66 |
| 1958 | 54 |
| 1959 | 38 |
| 1960 | 36 |
| 1961 | 38 |
| 1963 | 20 |
| 1964 | 14 |
| 1965 | 13 |
| 1966 | 13 |
| 1967 | 11 |
| 1968 | 17 |
| 1969 | 9 |
| 1970 | 9 |
| 1971 | 10 |
| 1972 | 8 |
| 1973 | 15 |
| 1976 | 10 |
| 1977 | 18 |
| 1978 | 10 |
| 1982 | 5 |
| 1983 | 5 |
| 1985 | 5 |
| 1996 | 5 |
| 1997 | 5 |
| 1998 | 5 |
| 1999 | 5 |
| 2006 | 5 |