| Year | Count |
|---|---|
| 1979 | 10 |
| 1983 | 12 |
| 1985 | 19 |
| 1986 | 8 |
| 1987 | 17 |
| 1988 | 15 |
| 1989 | 7 |
| 1990 | 8 |
| 1991 | 8 |
| 1993 | 10 |
| 1994 | 24 |
| 1995 | 49 |
| 1996 | 53 |
| 1997 | 62 |
| 1998 | 87 |
| 1999 | 28 |
| 2000 | 50 |
| 2001 | 56 |
| 2002 | 41 |
| 2003 | 111 |
| 2004 | 86 |
| 2005 | 138 |
| 2006 | 115 |
| 2007 | 178 |
| 2008 | 194 |
| 2009 | 133 |
| 2010 | 176 |
| 2011 | 212 |
| 2012 | 239 |
| 2013 | 213 |
| 2014 | 213 |
| 2015 | 395 |
| 2016 | 452 |
| 2017 | 557 |
| 2018 | 485 |
| 2019 | 523 |
| 2020 | 519 |
| 2021 | 437 |
| 2022 | 573 |
| 2023 | 619 |
| 2024 | 605 |