| Year | Count |
|---|---|
| 1987 | 10 |
| 1990 | 5 |
| 1991 | 17 |
| 1992 | 29 |
| 1993 | 18 |
| 1994 | 41 |
| 1995 | 69 |
| 1996 | 107 |
| 1997 | 119 |
| 1998 | 187 |
| 1999 | 259 |
| 2000 | 207 |
| 2001 | 198 |
| 2002 | 147 |
| 2003 | 206 |
| 2004 | 257 |
| 2005 | 281 |
| 2006 | 207 |
| 2007 | 294 |
| 2008 | 290 |
| 2009 | 291 |
| 2010 | 195 |
| 2011 | 197 |
| 2012 | 141 |
| 2013 | 78 |
| 2014 | 146 |
| 2015 | 200 |
| 2016 | 103 |
| 2017 | 81 |
| 2018 | 38 |
| 2019 | 51 |
| 2020 | 84 |
| 2021 | 39 |
| 2022 | 11 |
| 2023 | 48 |
| 2024 | 16 |