| Year | Count |
|---|---|
| 1982 | 15 |
| 1983 | 28 |
| 1984 | 54 |
| 1985 | 108 |
| 1986 | 161 |
| 1987 | 226 |
| 1988 | 280 |
| 1989 | 338 |
| 1990 | 382 |
| 1991 | 340 |
| 1992 | 543 |
| 1993 | 425 |
| 1994 | 421 |
| 1995 | 426 |
| 1996 | 427 |
| 1997 | 424 |
| 1998 | 455 |
| 1999 | 442 |
| 2000 | 513 |
| 2001 | 484 |
| 2002 | 444 |
| 2003 | 455 |
| 2004 | 396 |
| 2005 | 399 |
| 2006 | 352 |
| 2007 | 309 |
| 2008 | 317 |
| 2009 | 279 |
| 2010 | 211 |
| 2011 | 212 |
| 2012 | 185 |
| 2013 | 169 |
| 2014 | 157 |
| 2015 | 121 |
| 2016 | 255 |
| 2017 | 186 |
| 2018 | 240 |
| 2019 | 108 |
| 2020 | 78 |
| 2021 | 70 |
| 2022 | 60 |
| 2023 | 66 |
| 2024 | 80 |