| Year | Count |
|---|---|
| 1975 | 5 |
| 1976 | 20 |
| 1977 | 47 |
| 1978 | 25 |
| 1979 | 18 |
| 1980 | 11 |
| 1981 | 39 |
| 1982 | 36 |
| 1983 | 30 |
| 1984 | 26 |
| 1985 | 68 |
| 1986 | 71 |
| 1987 | 72 |
| 1988 | 127 |
| 1989 | 93 |
| 1990 | 135 |
| 1991 | 117 |
| 1992 | 146 |
| 1993 | 169 |
| 1994 | 110 |
| 1995 | 146 |
| 1996 | 158 |
| 1997 | 219 |
| 1998 | 181 |
| 1999 | 123 |
| 2000 | 206 |
| 2001 | 230 |
| 2002 | 127 |
| 2003 | 177 |
| 2004 | 232 |
| 2005 | 189 |
| 2006 | 124 |
| 2007 | 183 |
| 2008 | 107 |
| 2009 | 54 |
| 2010 | 111 |
| 2011 | 152 |
| 2012 | 57 |
| 2013 | 91 |
| 2014 | 111 |
| 2015 | 70 |
| 2016 | 55 |
| 2017 | 56 |
| 2018 | 56 |
| 2019 | 51 |
| 2020 | 27 |
| 2021 | 51 |
| 2022 | 23 |
| 2023 | 38 |
| 2024 | 36 |