| Year | Count |
|---|---|
| 1977 | 5 |
| 1981 | 7 |
| 1982 | 16 |
| 1983 | 5 |
| 1984 | 34 |
| 1985 | 21 |
| 1986 | 31 |
| 1987 | 47 |
| 1988 | 20 |
| 1989 | 81 |
| 1990 | 147 |
| 1991 | 161 |
| 1992 | 227 |
| 1993 | 195 |
| 1994 | 266 |
| 1995 | 246 |
| 1996 | 332 |
| 1997 | 343 |
| 1998 | 322 |
| 1999 | 351 |
| 2000 | 332 |
| 2001 | 371 |
| 2002 | 343 |
| 2003 | 468 |
| 2004 | 689 |
| 2005 | 776 |
| 2006 | 802 |
| 2007 | 935 |
| 2008 | 1,106 |
| 2009 | 1,527 |
| 2010 | 1,752 |
| 2011 | 2,928 |
| 2012 | 3,246 |
| 2013 | 2,981 |
| 2014 | 3,003 |
| 2015 | 2,924 |
| 2016 | 3,413 |
| 2017 | 3,571 |
| 2018 | 3,488 |
| 2019 | 3,157 |
| 2020 | 2,939 |
| 2021 | 2,840 |
| 2022 | 3,000 |
| 2023 | 2,495 |
| 2024 | 2,462 |