| Year | Count |
|---|---|
| 1977 | 5 |
| 1982 | 18 |
| 1985 | 34 |
| 1986 | 10 |
| 1987 | 6 |
| 1988 | 5 |
| 1989 | 16 |
| 1990 | 32 |
| 1991 | 34 |
| 1992 | 36 |
| 1993 | 57 |
| 1994 | 159 |
| 1995 | 170 |
| 1996 | 113 |
| 1997 | 156 |
| 1998 | 167 |
| 1999 | 174 |
| 2000 | 146 |
| 2001 | 181 |
| 2002 | 87 |
| 2003 | 124 |
| 2004 | 152 |
| 2005 | 182 |
| 2006 | 144 |
| 2007 | 129 |
| 2008 | 160 |
| 2009 | 122 |
| 2010 | 121 |
| 2011 | 120 |
| 2012 | 84 |
| 2013 | 97 |
| 2014 | 89 |
| 2015 | 130 |
| 2016 | 73 |
| 2017 | 67 |
| 2018 | 80 |
| 2019 | 60 |
| 2020 | 57 |
| 2021 | 46 |
| 2022 | 22 |
| 2023 | 22 |
| 2024 | 23 |