| Year | Count |
|---|---|
| 1977 | 28 |
| 1978 | 76 |
| 1979 | 48 |
| 1980 | 53 |
| 1981 | 47 |
| 1982 | 42 |
| 1983 | 60 |
| 1984 | 42 |
| 1985 | 62 |
| 1986 | 63 |
| 1987 | 92 |
| 1988 | 101 |
| 1989 | 115 |
| 1990 | 117 |
| 1991 | 45 |
| 1992 | 62 |
| 1993 | 98 |
| 1994 | 23 |
| 1995 | 144 |
| 1996 | 126 |
| 1997 | 177 |
| 1998 | 154 |
| 1999 | 193 |
| 2000 | 188 |
| 2001 | 177 |
| 2002 | 168 |
| 2003 | 269 |
| 2004 | 386 |
| 2005 | 433 |
| 2006 | 454 |
| 2007 | 389 |
| 2008 | 302 |
| 2009 | 317 |
| 2010 | 316 |
| 2011 | 328 |
| 2012 | 371 |
| 2013 | 235 |
| 2014 | 200 |
| 2015 | 351 |
| 2016 | 352 |
| 2017 | 405 |
| 2018 | 343 |
| 2019 | 397 |
| 2020 | 349 |
| 2021 | 313 |
| 2022 | 276 |
| 2023 | 239 |
| 2024 | 178 |