| Year | Count |
|---|---|
| 1980 | 5 |
| 1981 | 6 |
| 1984 | 11 |
| 1985 | 12 |
| 1986 | 35 |
| 1987 | 55 |
| 1988 | 15 |
| 1989 | 39 |
| 1990 | 102 |
| 1991 | 70 |
| 1992 | 80 |
| 1993 | 73 |
| 1994 | 11 |
| 1995 | 29 |
| 1996 | 70 |
| 1997 | 65 |
| 1998 | 77 |
| 1999 | 113 |
| 2000 | 68 |
| 2001 | 11 |
| 2002 | 21 |
| 2003 | 71 |
| 2004 | 106 |
| 2005 | 93 |
| 2006 | 84 |
| 2007 | 99 |
| 2008 | 113 |
| 2009 | 121 |
| 2010 | 86 |
| 2011 | 87 |
| 2012 | 27 |
| 2013 | 47 |
| 2014 | 17 |
| 2015 | 35 |
| 2016 | 36 |
| 2017 | 20 |
| 2018 | 13 |
| 2019 | 11 |
| 2020 | 5 |
| 2021 | 5 |
| 2022 | 6 |