| Year | Count |
|---|---|
| 1988 | 5 |
| 1990 | 7 |
| 1992 | 9 |
| 1993 | 15 |
| 1994 | 12 |
| 1995 | 11 |
| 1996 | 11 |
| 1997 | 13 |
| 1998 | 18 |
| 1999 | 26 |
| 2000 | 38 |
| 2001 | 30 |
| 2002 | 33 |
| 2003 | 53 |
| 2004 | 43 |
| 2005 | 50 |
| 2006 | 44 |
| 2007 | 52 |
| 2008 | 58 |
| 2009 | 79 |
| 2010 | 58 |
| 2011 | 54 |
| 2012 | 60 |
| 2013 | 52 |
| 2014 | 51 |
| 2015 | 36 |
| 2016 | 96 |
| 2017 | 141 |
| 2018 | 28 |
| 2019 | 60 |
| 2020 | 48 |
| 2021 | 52 |
| 2022 | 26 |
| 2023 | 28 |
| 2024 | 24 |