| Year | Count |
|---|---|
| 1980 | 5 |
| 1981 | 20 |
| 1983 | 5 |
| 1985 | 10 |
| 1987 | 12 |
| 1988 | 17 |
| 1989 | 12 |
| 1990 | 17 |
| 1991 | 15 |
| 1992 | 18 |
| 1993 | 16 |
| 1994 | 40 |
| 1995 | 15 |
| 1996 | 46 |
| 1997 | 32 |
| 1998 | 92 |
| 1999 | 70 |
| 2000 | 118 |
| 2001 | 112 |
| 2002 | 105 |
| 2003 | 98 |
| 2004 | 110 |
| 2005 | 142 |
| 2006 | 89 |
| 2007 | 133 |
| 2008 | 185 |
| 2009 | 153 |
| 2010 | 166 |
| 2011 | 179 |
| 2012 | 200 |
| 2013 | 236 |
| 2014 | 273 |
| 2015 | 306 |
| 2016 | 377 |
| 2017 | 381 |
| 2018 | 326 |
| 2019 | 299 |
| 2020 | 227 |
| 2021 | 281 |
| 2022 | 243 |
| 2023 | 268 |
| 2024 | 324 |