| Year | Count |
|---|---|
| 1981 | 5 |
| 1983 | 5 |
| 1984 | 12 |
| 1985 | 57 |
| 1986 | 75 |
| 1987 | 83 |
| 1988 | 83 |
| 1989 | 87 |
| 1990 | 193 |
| 1991 | 188 |
| 1992 | 223 |
| 1993 | 410 |
| 1994 | 900 |
| 1995 | 837 |
| 1996 | 1,128 |
| 1997 | 1,176 |
| 1998 | 1,184 |
| 1999 | 809 |
| 2000 | 661 |
| 2001 | 546 |
| 2002 | 411 |
| 2003 | 402 |
| 2004 | 555 |
| 2005 | 567 |
| 2006 | 386 |
| 2007 | 461 |
| 2008 | 550 |
| 2009 | 500 |
| 2010 | 626 |
| 2011 | 670 |
| 2012 | 453 |
| 2013 | 358 |
| 2014 | 465 |
| 2015 | 443 |
| 2016 | 490 |
| 2017 | 443 |
| 2018 | 334 |
| 2019 | 340 |
| 2020 | 320 |
| 2021 | 369 |
| 2022 | 466 |
| 2023 | 325 |
| 2024 | 249 |