| Year | Count |
|---|---|
| 1974 | 5 |
| 1977 | 6 |
| 1978 | 21 |
| 1980 | 28 |
| 1981 | 57 |
| 1982 | 65 |
| 1983 | 43 |
| 1984 | 77 |
| 1985 | 129 |
| 1986 | 102 |
| 1987 | 137 |
| 1988 | 131 |
| 1989 | 135 |
| 1990 | 188 |
| 1991 | 403 |
| 1992 | 430 |
| 1993 | 449 |
| 1994 | 406 |
| 1995 | 371 |
| 1996 | 387 |
| 1997 | 362 |
| 1998 | 412 |
| 1999 | 338 |
| 2000 | 316 |
| 2001 | 322 |
| 2002 | 227 |
| 2003 | 300 |
| 2004 | 414 |
| 2005 | 401 |
| 2006 | 235 |
| 2007 | 236 |
| 2008 | 321 |
| 2009 | 219 |
| 2010 | 266 |
| 2011 | 221 |
| 2012 | 156 |
| 2013 | 248 |
| 2014 | 88 |
| 2015 | 125 |
| 2016 | 148 |
| 2017 | 103 |
| 2018 | 68 |
| 2019 | 36 |
| 2020 | 29 |
| 2021 | 25 |
| 2022 | 20 |
| 2023 | 25 |
| 2024 | 22 |