| Year | Count |
|---|---|
| 1974 | 7 |
| 1975 | 5 |
| 1977 | 8 |
| 1982 | 6 |
| 1983 | 11 |
| 1984 | 14 |
| 1985 | 21 |
| 1986 | 25 |
| 1987 | 36 |
| 1988 | 39 |
| 1989 | 39 |
| 1990 | 70 |
| 1991 | 148 |
| 1992 | 205 |
| 1993 | 176 |
| 1994 | 148 |
| 1995 | 128 |
| 1996 | 123 |
| 1997 | 154 |
| 1998 | 130 |
| 1999 | 124 |
| 2000 | 117 |
| 2001 | 102 |
| 2002 | 92 |
| 2003 | 98 |
| 2004 | 103 |
| 2005 | 79 |
| 2006 | 79 |
| 2007 | 80 |
| 2008 | 68 |
| 2009 | 62 |
| 2010 | 54 |
| 2011 | 48 |
| 2012 | 39 |
| 2013 | 42 |
| 2014 | 38 |
| 2015 | 37 |
| 2016 | 82 |
| 2017 | 64 |
| 2018 | 38 |
| 2019 | 54 |
| 2020 | 19 |
| 2021 | 21 |
| 2022 | 13 |
| 2023 | 12 |
| 2024 | 12 |