| Year | Count |
|---|---|
| 1991 | 13 |
| 1992 | 12 |
| 1993 | 9 |
| 1995 | 12 |
| 1996 | 12 |
| 1997 | 14 |
| 1998 | 15 |
| 1999 | 14 |
| 2000 | 28 |
| 2001 | 17 |
| 2002 | 40 |
| 2003 | 50 |
| 2004 | 49 |
| 2005 | 72 |
| 2006 | 99 |
| 2007 | 108 |
| 2008 | 123 |
| 2009 | 121 |
| 2010 | 198 |
| 2011 | 252 |
| 2012 | 317 |
| 2013 | 325 |
| 2014 | 303 |
| 2015 | 310 |
| 2016 | 882 |
| 2017 | 813 |
| 2018 | 921 |
| 2019 | 564 |
| 2020 | 506 |
| 2021 | 510 |
| 2022 | 442 |
| 2023 | 444 |
| 2024 | 336 |