| Year | Count |
|---|---|
| 1965 | 5 |
| 1966 | 24 |
| 1967 | 33 |
| 1968 | 40 |
| 1969 | 27 |
| 1970 | 43 |
| 1971 | 48 |
| 1972 | 53 |
| 1973 | 51 |
| 1974 | 60 |
| 1975 | 41 |
| 1976 | 53 |
| 1977 | 29 |
| 1978 | 33 |
| 1979 | 17 |
| 1980 | 25 |
| 1981 | 31 |
| 1982 | 16 |
| 1983 | 13 |
| 1984 | 13 |
| 1985 | 17 |
| 1986 | 9 |
| 1987 | 7 |
| 1988 | 14 |
| 1989 | 13 |
| 1991 | 8 |
| 1994 | 8 |
| 1995 | 5 |
| 1998 | 6 |
| 2000 | 5 |
| 2002 | 7 |
| 2003 | 7 |
| 2004 | 8 |
| 2007 | 5 |
| 2008 | 6 |
| 2009 | 11 |
| 2010 | 11 |
| 2011 | 8 |
| 2012 | 7 |
| 2013 | 8 |
| 2014 | 9 |
| 2015 | 10 |
| 2016 | 10 |
| 2019 | 5 |
| 2020 | 5 |
| 2021 | 7 |
| 2022 | 9 |
| 2024 | 12 |