| Year | Count |
|---|---|
| 1958 | 6 |
| 1960 | 5 |
| 1962 | 6 |
| 1964 | 7 |
| 1965 | 7 |
| 1966 | 5 |
| 1968 | 12 |
| 1969 | 6 |
| 1970 | 5 |
| 1971 | 9 |
| 1972 | 8 |
| 1973 | 5 |
| 1975 | 6 |
| 1976 | 6 |
| 1977 | 6 |
| 1980 | 7 |
| 1981 | 6 |
| 1982 | 6 |
| 1983 | 7 |
| 1984 | 10 |
| 1985 | 8 |
| 1989 | 6 |
| 1990 | 9 |
| 1991 | 6 |
| 1992 | 8 |
| 1993 | 6 |
| 1994 | 5 |
| 1995 | 5 |
| 1996 | 6 |
| 1997 | 5 |
| 1998 | 5 |
| 2007 | 9 |
| 2008 | 7 |
| 2015 | 10 |
| 2018 | 10 |