| Year | Count |
|---|---|
| 1973 | 12 |
| 1974 | 35 |
| 1975 | 28 |
| 1976 | 68 |
| 1977 | 63 |
| 1978 | 82 |
| 1979 | 81 |
| 1980 | 69 |
| 1981 | 74 |
| 1982 | 59 |
| 1983 | 55 |
| 1984 | 47 |
| 1985 | 70 |
| 1986 | 31 |
| 1987 | 64 |
| 1988 | 78 |
| 1989 | 101 |
| 1990 | 98 |
| 1991 | 169 |
| 1992 | 220 |
| 1993 | 220 |
| 1994 | 169 |
| 1995 | 151 |
| 1996 | 179 |
| 1997 | 169 |
| 1998 | 147 |
| 1999 | 173 |
| 2000 | 208 |
| 2001 | 262 |
| 2002 | 300 |
| 2003 | 408 |
| 2004 | 484 |
| 2005 | 484 |
| 2006 | 518 |
| 2007 | 468 |
| 2008 | 378 |
| 2009 | 272 |
| 2010 | 269 |
| 2011 | 244 |
| 2012 | 252 |
| 2013 | 194 |
| 2014 | 203 |
| 2015 | 271 |
| 2016 | 300 |
| 2017 | 331 |
| 2018 | 318 |
| 2019 | 262 |
| 2020 | 257 |
| 2021 | 333 |
| 2022 | 230 |
| 2023 | 265 |
| 2024 | 219 |