| Year | Count |
|---|---|
| 1982 | 8 |
| 1984 | 5 |
| 1986 | 6 |
| 1987 | 5 |
| 1988 | 9 |
| 1989 | 8 |
| 1990 | 11 |
| 1991 | 19 |
| 1992 | 23 |
| 1993 | 30 |
| 1994 | 22 |
| 1995 | 25 |
| 1996 | 23 |
| 1997 | 23 |
| 1998 | 26 |
| 1999 | 23 |
| 2000 | 20 |
| 2001 | 31 |
| 2002 | 25 |
| 2003 | 32 |
| 2004 | 38 |
| 2005 | 45 |
| 2006 | 31 |
| 2007 | 54 |
| 2008 | 64 |
| 2009 | 83 |
| 2010 | 120 |
| 2011 | 151 |
| 2012 | 174 |
| 2013 | 191 |
| 2014 | 162 |
| 2015 | 162 |
| 2016 | 531 |
| 2017 | 516 |
| 2018 | 537 |
| 2019 | 334 |
| 2020 | 324 |
| 2021 | 280 |
| 2022 | 270 |
| 2023 | 220 |
| 2024 | 222 |