| Year | Count |
|---|---|
| 1935 | 10 |
| 1938 | 12 |
| 1939 | 21 |
| 1940 | 14 |
| 1941 | 25 |
| 1942 | 30 |
| 1943 | 45 |
| 1944 | 33 |
| 1945 | 44 |
| 1946 | 45 |
| 1947 | 100 |
| 1948 | 65 |
| 1949 | 70 |
| 1950 | 49 |
| 1951 | 117 |
| 1952 | 119 |
| 1953 | 148 |
| 1954 | 164 |
| 1955 | 227 |
| 1956 | 243 |
| 1957 | 327 |
| 1958 | 412 |
| 1959 | 321 |
| 1960 | 349 |
| 1961 | 313 |
| 1962 | 200 |
| 1963 | 278 |
| 1964 | 242 |
| 1965 | 180 |
| 1966 | 159 |
| 1967 | 181 |
| 1968 | 133 |
| 1969 | 107 |
| 1970 | 137 |
| 1971 | 83 |
| 1972 | 94 |
| 1973 | 59 |
| 1974 | 34 |
| 1975 | 34 |
| 1976 | 27 |
| 1977 | 30 |
| 1978 | 39 |
| 1979 | 16 |
| 1980 | 29 |
| 1981 | 57 |
| 1982 | 34 |
| 1983 | 5 |
| 1984 | 5 |
| 1985 | 26 |
| 1988 | 10 |
| 1989 | 12 |
| 1990 | 10 |
| 1994 | 10 |