| Year | Count |
|---|---|
| 1950 | 8 |
| 1955 | 6 |
| 1958 | 11 |
| 1959 | 7 |
| 1960 | 6 |
| 1961 | 12 |
| 1962 | 5 |
| 1963 | 11 |
| 1964 | 8 |
| 1965 | 8 |
| 1966 | 5 |
| 1967 | 15 |
| 1968 | 9 |
| 1969 | 6 |
| 1970 | 8 |
| 1971 | 7 |
| 1972 | 7 |
| 1973 | 5 |
| 1975 | 9 |
| 1976 | 7 |
| 1979 | 7 |
| 1981 | 13 |
| 1982 | 6 |
| 1985 | 5 |
| 1986 | 6 |
| 1990 | 5 |
| 1991 | 8 |
| 1992 | 10 |
| 1994 | 5 |
| 1995 | 7 |
| 2000 | 6 |
| 2005 | 6 |
| 2006 | 6 |
| 2009 | 5 |
| 2010 | 6 |
| 2014 | 5 |
| 2017 | 10 |