| Year | Count |
|---|---|
| 1991 | 10 |
| 1992 | 5 |
| 1993 | 10 |
| 1994 | 22 |
| 1995 | 37 |
| 1996 | 30 |
| 1997 | 51 |
| 1998 | 40 |
| 1999 | 29 |
| 2000 | 76 |
| 2001 | 74 |
| 2002 | 87 |
| 2003 | 103 |
| 2004 | 161 |
| 2005 | 184 |
| 2006 | 146 |
| 2007 | 207 |
| 2008 | 270 |
| 2009 | 150 |
| 2010 | 292 |
| 2011 | 262 |
| 2012 | 238 |
| 2013 | 224 |
| 2014 | 239 |
| 2015 | 273 |
| 2016 | 239 |
| 2017 | 187 |
| 2018 | 163 |
| 2019 | 139 |
| 2020 | 133 |
| 2021 | 100 |
| 2022 | 45 |
| 2023 | 60 |
| 2024 | 21 |