| Year | Count |
|---|---|
| 1990 | 6 |
| 1993 | 23 |
| 1994 | 41 |
| 1995 | 51 |
| 1996 | 38 |
| 1997 | 82 |
| 1998 | 148 |
| 1999 | 154 |
| 2000 | 135 |
| 2001 | 142 |
| 2002 | 72 |
| 2003 | 111 |
| 2004 | 175 |
| 2005 | 174 |
| 2006 | 136 |
| 2007 | 105 |
| 2008 | 84 |
| 2009 | 63 |
| 2010 | 129 |
| 2011 | 38 |
| 2012 | 48 |
| 2013 | 53 |
| 2014 | 17 |
| 2015 | 20 |
| 2016 | 38 |
| 2017 | 27 |
| 2018 | 7 |
| 2019 | 19 |
| 2020 | 6 |
| 2022 | 5 |