| Year | Count |
|---|---|
| 1950 | 8 |
| 1951 | 12 |
| 1952 | 10 |
| 1953 | 21 |
| 1954 | 12 |
| 1955 | 10 |
| 1956 | 12 |
| 1957 | 16 |
| 1958 | 22 |
| 1959 | 14 |
| 1960 | 26 |
| 1961 | 8 |
| 1963 | 12 |
| 1964 | 9 |
| 1965 | 15 |
| 1966 | 13 |
| 1967 | 8 |
| 1968 | 14 |
| 1969 | 13 |
| 1970 | 9 |
| 1971 | 14 |
| 1972 | 10 |
| 1974 | 6 |
| 1975 | 6 |
| 1976 | 14 |
| 1977 | 22 |
| 1978 | 14 |
| 1979 | 10 |
| 1982 | 5 |
| 1984 | 8 |
| 1985 | 8 |
| 1986 | 5 |
| 1987 | 9 |
| 1988 | 6 |
| 1991 | 6 |
| 1992 | 11 |
| 1993 | 5 |
| 1995 | 8 |
| 1996 | 6 |
| 1999 | 6 |
| 2000 | 8 |
| 2001 | 7 |
| 2002 | 6 |
| 2003 | 5 |
| 2006 | 6 |
| 2007 | 6 |
| 2008 | 6 |
| 2009 | 7 |
| 2011 | 7 |
| 2013 | 5 |
| 2014 | 6 |
| 2016 | 15 |
| 2018 | 12 |