| Year | Count |
|---|---|
| 1934 | 5 |
| 1937 | 5 |
| 1946 | 5 |
| 1948 | 7 |
| 1949 | 6 |
| 1950 | 6 |
| 1951 | 6 |
| 1956 | 7 |
| 1957 | 14 |
| 1959 | 6 |
| 1960 | 11 |
| 1961 | 6 |
| 1963 | 7 |
| 1964 | 6 |
| 1965 | 9 |
| 1966 | 12 |
| 1967 | 5 |
| 1968 | 10 |
| 1970 | 12 |
| 1971 | 6 |
| 1972 | 17 |
| 1973 | 7 |
| 1974 | 12 |
| 1975 | 9 |
| 1976 | 10 |
| 1977 | 10 |
| 1978 | 5 |
| 1979 | 9 |
| 1980 | 5 |
| 1981 | 8 |
| 1982 | 12 |
| 1984 | 7 |
| 1985 | 9 |
| 1986 | 8 |
| 1987 | 7 |
| 1988 | 8 |
| 1989 | 5 |
| 1990 | 6 |
| 1991 | 7 |
| 1995 | 6 |
| 1998 | 5 |
| 1999 | 5 |
| 2001 | 5 |
| 2007 | 5 |
| 2008 | 5 |
| 2013 | 5 |