| Year | Count |
|---|---|
| 1950 | 5 |
| 1951 | 7 |
| 1953 | 8 |
| 1954 | 5 |
| 1956 | 5 |
| 1957 | 10 |
| 1960 | 10 |
| 1961 | 6 |
| 1962 | 5 |
| 1963 | 8 |
| 1965 | 6 |
| 1966 | 6 |
| 1969 | 11 |
| 1970 | 10 |
| 1971 | 5 |
| 1972 | 8 |
| 1973 | 11 |
| 1976 | 8 |
| 1977 | 5 |
| 1978 | 12 |
| 1980 | 6 |
| 1982 | 8 |
| 1983 | 8 |
| 1984 | 11 |
| 1985 | 15 |
| 1986 | 13 |
| 1987 | 12 |
| 1988 | 9 |
| 1989 | 10 |
| 1990 | 14 |
| 1991 | 12 |
| 1992 | 14 |
| 1993 | 7 |
| 1994 | 9 |
| 1995 | 11 |
| 1996 | 8 |
| 1997 | 14 |
| 1998 | 20 |
| 1999 | 13 |
| 2000 | 18 |
| 2001 | 15 |
| 2002 | 16 |
| 2003 | 32 |
| 2004 | 25 |
| 2005 | 13 |
| 2006 | 19 |
| 2007 | 28 |
| 2008 | 31 |
| 2009 | 47 |
| 2010 | 45 |
| 2011 | 43 |
| 2012 | 33 |
| 2013 | 40 |
| 2014 | 24 |
| 2015 | 43 |
| 2016 | 49 |
| 2017 | 69 |
| 2018 | 69 |
| 2019 | 57 |
| 2020 | 32 |
| 2021 | 46 |
| 2022 | 47 |
| 2023 | 45 |
| 2024 | 44 |