| Year | Count |
|---|---|
| 1989 | 6 |
| 1990 | 15 |
| 1991 | 16 |
| 1992 | 10 |
| 1993 | 14 |
| 1995 | 14 |
| 1996 | 9 |
| 1997 | 12 |
| 1998 | 14 |
| 1999 | 9 |
| 2000 | 13 |
| 2001 | 5 |
| 2002 | 19 |
| 2003 | 16 |
| 2004 | 20 |
| 2005 | 23 |
| 2006 | 23 |
| 2007 | 20 |
| 2008 | 24 |
| 2009 | 28 |
| 2010 | 34 |
| 2011 | 40 |
| 2012 | 39 |
| 2013 | 33 |
| 2014 | 39 |
| 2015 | 29 |
| 2016 | 52 |
| 2017 | 64 |
| 2018 | 58 |
| 2019 | 70 |
| 2020 | 32 |
| 2021 | 32 |
| 2022 | 46 |
| 2023 | 54 |
| 2024 | 44 |