| Year | Count |
|---|---|
| 1938 | 5 |
| 1940 | 6 |
| 1942 | 10 |
| 1946 | 10 |
| 1947 | 7 |
| 1948 | 26 |
| 1949 | 14 |
| 1950 | 41 |
| 1951 | 24 |
| 1952 | 26 |
| 1953 | 25 |
| 1954 | 69 |
| 1955 | 20 |
| 1956 | 22 |
| 1957 | 17 |
| 1959 | 7 |
| 1960 | 8 |
| 1961 | 40 |
| 1962 | 7 |
| 1964 | 20 |
| 1966 | 11 |
| 1967 | 32 |
| 1968 | 20 |
| 1969 | 19 |
| 1970 | 69 |
| 1971 | 59 |
| 1972 | 31 |
| 1973 | 13 |
| 1974 | 31 |
| 1975 | 17 |
| 1976 | 10 |
| 1977 | 23 |
| 1980 | 5 |
| 1981 | 6 |
| 1982 | 7 |
| 1983 | 5 |
| 1984 | 5 |
| 1988 | 10 |