| Year | Count |
|---|---|
| 1975 | 10 |
| 1976 | 5 |
| 1978 | 12 |
| 1979 | 6 |
| 1980 | 25 |
| 1981 | 7 |
| 1982 | 7 |
| 1983 | 65 |
| 1984 | 26 |
| 1985 | 58 |
| 1986 | 38 |
| 1987 | 68 |
| 1988 | 83 |
| 1989 | 87 |
| 1990 | 103 |
| 1991 | 135 |
| 1992 | 199 |
| 1993 | 171 |
| 1994 | 146 |
| 1995 | 120 |
| 1996 | 122 |
| 1997 | 101 |
| 1998 | 205 |
| 1999 | 146 |
| 2000 | 186 |
| 2001 | 258 |
| 2002 | 158 |
| 2003 | 191 |
| 2004 | 248 |
| 2005 | 205 |
| 2006 | 197 |
| 2007 | 386 |
| 2008 | 770 |
| 2009 | 673 |
| 2010 | 607 |
| 2011 | 545 |
| 2012 | 582 |
| 2013 | 666 |
| 2014 | 548 |
| 2015 | 465 |
| 2016 | 448 |
| 2017 | 330 |
| 2018 | 278 |
| 2019 | 238 |
| 2020 | 244 |
| 2021 | 325 |
| 2022 | 103 |
| 2023 | 134 |
| 2024 | 80 |