| Year | Count |
|---|---|
| 1980 | 5 |
| 1982 | 5 |
| 1983 | 6 |
| 1984 | 5 |
| 1987 | 6 |
| 1989 | 6 |
| 1990 | 6 |
| 1991 | 6 |
| 1992 | 11 |
| 1993 | 14 |
| 1994 | 17 |
| 1995 | 17 |
| 1996 | 17 |
| 1997 | 17 |
| 1998 | 22 |
| 1999 | 21 |
| 2000 | 24 |
| 2001 | 15 |
| 2002 | 21 |
| 2003 | 24 |
| 2004 | 28 |
| 2005 | 19 |
| 2006 | 26 |
| 2007 | 21 |
| 2008 | 42 |
| 2009 | 35 |
| 2010 | 43 |
| 2011 | 45 |
| 2012 | 34 |
| 2013 | 42 |
| 2014 | 40 |
| 2015 | 41 |
| 2016 | 183 |
| 2017 | 186 |
| 2018 | 50 |
| 2019 | 110 |
| 2020 | 96 |
| 2021 | 80 |
| 2022 | 102 |
| 2023 | 96 |
| 2024 | 106 |