| Year | Count |
|---|---|
| 1966 | 5 |
| 1967 | 13 |
| 1968 | 16 |
| 1969 | 5 |
| 1970 | 12 |
| 1971 | 6 |
| 1972 | 7 |
| 1973 | 5 |
| 1974 | 10 |
| 1975 | 14 |
| 1976 | 22 |
| 1978 | 16 |
| 1979 | 22 |
| 1980 | 5 |
| 1981 | 9 |
| 1983 | 12 |
| 1984 | 7 |
| 1985 | 7 |
| 1986 | 10 |
| 1987 | 6 |
| 1989 | 6 |
| 1990 | 6 |
| 1991 | 5 |
| 1993 | 7 |
| 1994 | 9 |
| 1995 | 10 |
| 1996 | 22 |
| 1997 | 24 |
| 1999 | 7 |
| 2000 | 48 |
| 2001 | 53 |
| 2002 | 28 |
| 2003 | 56 |
| 2004 | 37 |
| 2005 | 73 |
| 2006 | 47 |
| 2007 | 38 |
| 2008 | 62 |
| 2009 | 44 |
| 2010 | 36 |
| 2011 | 36 |
| 2012 | 14 |
| 2013 | 12 |
| 2014 | 6 |
| 2015 | 25 |
| 2016 | 7 |
| 2017 | 10 |
| 2018 | 19 |
| 2019 | 10 |
| 2020 | 15 |
| 2021 | 15 |
| 2022 | 19 |
| 2023 | 59 |
| 2024 | 32 |