| Year | Count |
|---|---|
| 1975 | 6 |
| 1977 | 14 |
| 1981 | 9 |
| 1982 | 8 |
| 1983 | 19 |
| 1984 | 6 |
| 1985 | 19 |
| 1986 | 10 |
| 1987 | 15 |
| 1988 | 11 |
| 1989 | 21 |
| 1990 | 32 |
| 1991 | 44 |
| 1992 | 30 |
| 1993 | 88 |
| 1994 | 144 |
| 1995 | 79 |
| 1996 | 65 |
| 1997 | 118 |
| 1998 | 117 |
| 1999 | 92 |
| 2000 | 136 |
| 2001 | 201 |
| 2002 | 199 |
| 2003 | 233 |
| 2004 | 431 |
| 2005 | 507 |
| 2006 | 509 |
| 2007 | 534 |
| 2008 | 762 |
| 2009 | 622 |
| 2010 | 449 |
| 2011 | 679 |
| 2012 | 706 |
| 2013 | 449 |
| 2014 | 406 |
| 2015 | 513 |
| 2016 | 495 |
| 2017 | 600 |
| 2018 | 523 |
| 2019 | 457 |
| 2020 | 435 |
| 2021 | 451 |
| 2022 | 537 |
| 2023 | 669 |
| 2024 | 655 |