| Year | Count |
|---|---|
| 1945 | 12 |
| 1947 | 16 |
| 1948 | 13 |
| 1949 | 21 |
| 1950 | 15 |
| 1951 | 13 |
| 1952 | 10 |
| 1953 | 13 |
| 1954 | 22 |
| 1955 | 27 |
| 1956 | 21 |
| 1957 | 32 |
| 1958 | 50 |
| 1959 | 46 |
| 1960 | 64 |
| 1961 | 58 |
| 1963 | 28 |
| 1964 | 31 |
| 1965 | 26 |
| 1966 | 37 |
| 1967 | 23 |
| 1968 | 29 |
| 1969 | 30 |
| 1970 | 12 |
| 1971 | 16 |
| 1972 | 11 |
| 1973 | 15 |
| 1974 | 10 |
| 1975 | 17 |
| 1976 | 9 |
| 1977 | 12 |
| 1978 | 12 |
| 1979 | 28 |
| 1981 | 13 |
| 1982 | 5 |
| 1983 | 9 |
| 1985 | 9 |
| 1987 | 7 |
| 1988 | 13 |
| 1989 | 5 |
| 1990 | 7 |
| 1991 | 6 |
| 1992 | 7 |
| 1994 | 5 |
| 1995 | 9 |
| 1998 | 10 |
| 2001 | 8 |
| 2002 | 5 |
| 2003 | 7 |
| 2008 | 5 |
| 2014 | 6 |
| 2016 | 18 |