| Year | Count |
|---|---|
| 1977 | 6 |
| 1979 | 5 |
| 1982 | 6 |
| 1985 | 6 |
| 1987 | 6 |
| 1989 | 5 |
| 1992 | 8 |
| 1995 | 7 |
| 1997 | 6 |
| 1998 | 9 |
| 2000 | 9 |
| 2001 | 12 |
| 2002 | 20 |
| 2003 | 18 |
| 2004 | 14 |
| 2005 | 27 |
| 2006 | 35 |
| 2007 | 41 |
| 2008 | 36 |
| 2009 | 33 |
| 2010 | 30 |
| 2011 | 34 |
| 2012 | 5 |
| 2012 | 36 |
| 2013 | 29 |
| 2014 | 34 |
| 2015 | 33 |
| 2016 | 64 |
| 2017 | 60 |
| 2018 | 52 |
| 2019 | 62 |
| 2020 | 29 |
| 2021 | 34 |
| 2022 | 19 |
| 2023 | 23 |
| 2024 | 25 |