| Year | Count |
|---|---|
| 1989 | 5 |
| 1992 | 5 |
| 1993 | 6 |
| 1994 | 10 |
| 1995 | 27 |
| 1996 | 38 |
| 1997 | 47 |
| 1998 | 105 |
| 1999 | 233 |
| 2000 | 305 |
| 2001 | 458 |
| 2002 | 356 |
| 2003 | 387 |
| 2004 | 412 |
| 2005 | 310 |
| 2006 | 309 |
| 2007 | 280 |
| 2008 | 213 |
| 2009 | 122 |
| 2010 | 87 |
| 2011 | 60 |
| 2012 | 151 |
| 2013 | 132 |
| 2014 | 156 |
| 2015 | 160 |
| 2016 | 76 |
| 2017 | 97 |
| 2018 | 61 |
| 2019 | 65 |
| 2020 | 48 |
| 2021 | 27 |
| 2022 | 43 |
| 2023 | 35 |
| 2024 | 48 |