| Year | Count |
|---|---|
| 1979 | 5 |
| 1984 | 7 |
| 1988 | 6 |
| 1990 | 5 |
| 1991 | 5 |
| 1992 | 15 |
| 1993 | 38 |
| 1994 | 10 |
| 1995 | 10 |
| 1996 | 50 |
| 1997 | 63 |
| 1998 | 99 |
| 1999 | 67 |
| 2000 | 98 |
| 2001 | 129 |
| 2002 | 125 |
| 2003 | 155 |
| 2004 | 194 |
| 2005 | 295 |
| 2006 | 318 |
| 2007 | 406 |
| 2008 | 444 |
| 2009 | 460 |
| 2010 | 438 |
| 2011 | 558 |
| 2012 | 502 |
| 2013 | 446 |
| 2014 | 336 |
| 2015 | 333 |
| 2016 | 349 |
| 2017 | 434 |
| 2018 | 295 |
| 2019 | 236 |
| 2020 | 302 |
| 2021 | 278 |
| 2022 | 380 |
| 2023 | 280 |
| 2024 | 246 |