| Year | Count |
|---|---|
| 1949 | 5 |
| 1950 | 5 |
| 1953 | 6 |
| 1954 | 5 |
| 1959 | 6 |
| 1960 | 6 |
| 1963 | 7 |
| 1965 | 9 |
| 1966 | 7 |
| 1967 | 7 |
| 1969 | 10 |
| 1973 | 14 |
| 1975 | 6 |
| 1976 | 8 |
| 1977 | 9 |
| 1978 | 9 |
| 1979 | 8 |
| 1980 | 6 |
| 1982 | 8 |
| 1983 | 7 |
| 1984 | 7 |
| 1985 | 5 |
| 1986 | 5 |
| 1987 | 10 |
| 1988 | 8 |
| 1989 | 8 |
| 1990 | 7 |
| 1992 | 8 |
| 1993 | 7 |
| 1995 | 5 |
| 1996 | 6 |
| 1999 | 5 |
| 2003 | 7 |
| 2006 | 9 |
| 2007 | 5 |
| 2008 | 5 |
| 2009 | 5 |
| 2010 | 6 |
| 2012 | 5 |
| 2013 | 5 |
| 2015 | 16 |
| 2020 | 5 |