| Year | Count |
|---|---|
| 1973 | 5 |
| 1983 | 5 |
| 1984 | 7 |
| 1985 | 26 |
| 1986 | 47 |
| 1987 | 134 |
| 1988 | 135 |
| 1989 | 204 |
| 1990 | 252 |
| 1991 | 334 |
| 1992 | 456 |
| 1993 | 401 |
| 1994 | 516 |
| 1995 | 458 |
| 1996 | 465 |
| 1997 | 510 |
| 1998 | 532 |
| 1999 | 413 |
| 2000 | 412 |
| 2001 | 438 |
| 2002 | 351 |
| 2003 | 396 |
| 2004 | 483 |
| 2005 | 518 |
| 2006 | 463 |
| 2007 | 577 |
| 2008 | 421 |
| 2009 | 409 |
| 2010 | 338 |
| 2011 | 359 |
| 2012 | 242 |
| 2013 | 200 |
| 2014 | 208 |
| 2015 | 179 |
| 2016 | 107 |
| 2017 | 103 |
| 2018 | 86 |
| 2019 | 63 |
| 2020 | 25 |
| 2021 | 63 |
| 2022 | 20 |
| 2023 | 10 |
| 2024 | 18 |