| Year | Count |
|---|---|
| 1989 | 5 |
| 1992 | 9 |
| 1993 | 7 |
| 1994 | 5 |
| 1995 | 19 |
| 1996 | 25 |
| 1997 | 20 |
| 1998 | 73 |
| 1999 | 139 |
| 2000 | 130 |
| 2001 | 178 |
| 2002 | 145 |
| 2003 | 220 |
| 2004 | 225 |
| 2005 | 226 |
| 2006 | 243 |
| 2007 | 397 |
| 2008 | 386 |
| 2009 | 341 |
| 2010 | 454 |
| 2011 | 505 |
| 2012 | 601 |
| 2013 | 650 |
| 2014 | 635 |
| 2015 | 648 |
| 2016 | 599 |
| 2017 | 627 |
| 2018 | 492 |
| 2019 | 439 |
| 2020 | 367 |
| 2021 | 322 |
| 2022 | 273 |
| 2023 | 230 |
| 2024 | 214 |