| Year | Count |
|---|---|
| 1938 | 5 |
| 1942 | 6 |
| 1943 | 5 |
| 1947 | 5 |
| 1948 | 7 |
| 1949 | 5 |
| 1951 | 6 |
| 1952 | 6 |
| 1955 | 5 |
| 1956 | 9 |
| 1957 | 10 |
| 1958 | 22 |
| 1959 | 30 |
| 1960 | 24 |
| 1961 | 22 |
| 1963 | 24 |
| 1964 | 38 |
| 1965 | 51 |
| 1966 | 64 |
| 1967 | 83 |
| 1968 | 84 |
| 1969 | 83 |
| 1970 | 85 |
| 1971 | 80 |
| 1972 | 73 |
| 1973 | 57 |
| 1974 | 60 |
| 1975 | 55 |
| 1976 | 36 |
| 1977 | 74 |
| 1978 | 64 |
| 1979 | 50 |
| 1980 | 46 |
| 1981 | 19 |
| 1982 | 16 |
| 1983 | 19 |
| 1984 | 10 |
| 1985 | 13 |
| 1986 | 12 |
| 1987 | 6 |
| 1989 | 7 |
| 1990 | 8 |
| 1991 | 6 |
| 1993 | 5 |
| 1997 | 7 |
| 1999 | 5 |
| 2003 | 5 |