| Year | Count |
|---|---|
| 1981 | 15 |
| 1982 | 15 |
| 1983 | 11 |
| 1984 | 5 |
| 1985 | 6 |
| 1987 | 6 |
| 1988 | 5 |
| 1989 | 16 |
| 1990 | 5 |
| 1991 | 22 |
| 1992 | 14 |
| 1993 | 8 |
| 1994 | 13 |
| 1995 | 7 |
| 1996 | 18 |
| 1997 | 5 |
| 1998 | 41 |
| 1999 | 23 |
| 2000 | 46 |
| 2001 | 32 |
| 2002 | 25 |
| 2003 | 34 |
| 2004 | 37 |
| 2005 | 44 |
| 2006 | 43 |
| 2007 | 80 |
| 2008 | 73 |
| 2009 | 91 |
| 2010 | 81 |
| 2011 | 62 |
| 2012 | 18 |
| 2013 | 34 |
| 2014 | 45 |
| 2015 | 59 |
| 2016 | 62 |
| 2017 | 98 |
| 2018 | 57 |
| 2019 | 25 |
| 2020 | 35 |
| 2021 | 52 |
| 2022 | 61 |
| 2023 | 18 |
| 2024 | 38 |