| Year | Count |
|---|---|
| 1987 | 12 |
| 1989 | 15 |
| 1992 | 36 |
| 1993 | 37 |
| 1994 | 17 |
| 1995 | 33 |
| 1996 | 26 |
| 1997 | 144 |
| 1998 | 781 |
| 1999 | 530 |
| 2000 | 418 |
| 2001 | 421 |
| 2002 | 450 |
| 2003 | 396 |
| 2004 | 615 |
| 2005 | 544 |
| 2006 | 552 |
| 2007 | 462 |
| 2008 | 413 |
| 2009 | 322 |
| 2010 | 402 |
| 2011 | 466 |
| 2012 | 539 |
| 2013 | 463 |
| 2014 | 369 |
| 2015 | 367 |
| 2016 | 257 |
| 2017 | 218 |
| 2018 | 99 |
| 2019 | 117 |
| 2020 | 111 |
| 2021 | 98 |
| 2022 | 80 |
| 2023 | 82 |
| 2024 | 33 |