| Year | Count |
|---|---|
| 1980 | 5 |
| 1982 | 10 |
| 1983 | 10 |
| 1984 | 11 |
| 1985 | 24 |
| 1986 | 37 |
| 1987 | 21 |
| 1988 | 68 |
| 1989 | 82 |
| 1990 | 94 |
| 1991 | 325 |
| 1992 | 386 |
| 1993 | 309 |
| 1994 | 400 |
| 1995 | 346 |
| 1996 | 360 |
| 1997 | 469 |
| 1998 | 433 |
| 1999 | 361 |
| 2000 | 448 |
| 2001 | 431 |
| 2002 | 380 |
| 2003 | 442 |
| 2004 | 616 |
| 2005 | 614 |
| 2006 | 571 |
| 2007 | 601 |
| 2008 | 609 |
| 2009 | 443 |
| 2010 | 510 |
| 2011 | 521 |
| 2012 | 459 |
| 2013 | 487 |
| 2014 | 386 |
| 2015 | 507 |
| 2016 | 393 |
| 2017 | 370 |
| 2018 | 269 |
| 2019 | 268 |
| 2020 | 225 |
| 2021 | 213 |
| 2022 | 184 |
| 2023 | 110 |
| 2024 | 98 |