| Year | Count |
|---|---|
| 1980 | 10 |
| 1981 | 5 |
| 1982 | 5 |
| 1983 | 5 |
| 1984 | 13 |
| 1985 | 40 |
| 1986 | 33 |
| 1987 | 26 |
| 1988 | 14 |
| 1989 | 49 |
| 1990 | 75 |
| 1991 | 71 |
| 1992 | 92 |
| 1993 | 111 |
| 1994 | 97 |
| 1995 | 93 |
| 1996 | 84 |
| 1997 | 160 |
| 1998 | 142 |
| 1999 | 173 |
| 2000 | 159 |
| 2001 | 253 |
| 2002 | 163 |
| 2003 | 269 |
| 2004 | 330 |
| 2005 | 459 |
| 2006 | 579 |
| 2007 | 776 |
| 2008 | 829 |
| 2009 | 764 |
| 2010 | 726 |
| 2011 | 1,139 |
| 2012 | 1,144 |
| 2013 | 908 |
| 2014 | 794 |
| 2015 | 750 |
| 2016 | 736 |
| 2017 | 662 |
| 2018 | 467 |
| 2019 | 489 |
| 2020 | 330 |
| 2021 | 351 |
| 2022 | 339 |
| 2023 | 236 |
| 2024 | 268 |