| Year | Count |
|---|---|
| 1977 | 10 |
| 1978 | 21 |
| 1979 | 23 |
| 1982 | 27 |
| 1983 | 48 |
| 1984 | 39 |
| 1985 | 7 |
| 1986 | 58 |
| 1987 | 55 |
| 1988 | 83 |
| 1989 | 71 |
| 1990 | 152 |
| 1991 | 181 |
| 1992 | 233 |
| 1993 | 262 |
| 1994 | 286 |
| 1995 | 554 |
| 1996 | 463 |
| 1997 | 559 |
| 1998 | 708 |
| 1999 | 608 |
| 2000 | 498 |
| 2001 | 345 |
| 2002 | 225 |
| 2003 | 329 |
| 2004 | 377 |
| 2005 | 349 |
| 2006 | 404 |
| 2007 | 328 |
| 2008 | 366 |
| 2009 | 269 |
| 2010 | 293 |
| 2011 | 258 |
| 2012 | 279 |
| 2013 | 179 |
| 2014 | 156 |
| 2015 | 158 |
| 2016 | 101 |
| 2017 | 162 |
| 2018 | 148 |
| 2019 | 136 |
| 2020 | 170 |
| 2021 | 162 |
| 2022 | 315 |
| 2023 | 274 |
| 2024 | 267 |