| Year | Count |
|---|---|
| 1989 | 12 |
| 1990 | 12 |
| 1990 | 10 |
| 1991 | 12 |
| 1993 | 6 |
| 1994 | 5 |
| 1995 | 12 |
| 1997 | 20 |
| 1998 | 10 |
| 1999 | 15 |
| 1999 | 18 |
| 2000 | 43 |
| 2001 | 64 |
| 2002 | 36 |
| 2003 | 60 |
| 2004 | 49 |
| 2005 | 68 |
| 2006 | 76 |
| 2007 | 50 |
| 2008 | 59 |
| 2009 | 48 |
| 2010 | 46 |
| 2011 | 38 |
| 2012 | 55 |
| 2013 | 28 |
| 2014 | 45 |
| 2015 | 31 |
| 2016 | 22 |
| 2017 | 20 |
| 2018 | 22 |
| 2019 | 13 |
| 2020 | 17 |
| 2021 | 10 |
| 2022 | 10 |