| Year | Count |
|---|---|
| 1961 | 23 |
| 1964 | 5 |
| 1967 | 15 |
| 1968 | 5 |
| 1972 | 10 |
| 1976 | 20 |
| 1978 | 6 |
| 1979 | 27 |
| 1980 | 31 |
| 1981 | 14 |
| 1982 | 27 |
| 1983 | 25 |
| 1984 | 22 |
| 1985 | 5 |
| 1986 | 22 |
| 1987 | 32 |
| 1988 | 13 |
| 1989 | 21 |
| 1990 | 18 |
| 1991 | 39 |
| 1992 | 19 |
| 1993 | 15 |
| 1994 | 61 |
| 1995 | 7 |
| 1996 | 30 |
| 1997 | 34 |
| 1998 | 45 |
| 1999 | 66 |
| 2000 | 74 |
| 2001 | 106 |
| 2002 | 85 |
| 2003 | 117 |
| 2004 | 125 |
| 2005 | 154 |
| 2006 | 130 |
| 2007 | 136 |
| 2008 | 110 |
| 2009 | 77 |
| 2010 | 69 |
| 2011 | 69 |
| 2012 | 76 |
| 2013 | 20 |
| 2014 | 57 |
| 2015 | 64 |
| 2016 | 40 |
| 2017 | 20 |
| 2018 | 35 |
| 2019 | 23 |
| 2020 | 26 |
| 2021 | 20 |
| 2023 | 39 |
| 2024 | 19 |