| Year | Count |
|---|---|
| 1977 | 7 |
| 1978 | 5 |
| 1981 | 5 |
| 1989 | 5 |
| 1990 | 7 |
| 1993 | 9 |
| 1996 | 6 |
| 1997 | 7 |
| 1998 | 7 |
| 1999 | 12 |
| 2000 | 7 |
| 2001 | 9 |
| 2002 | 11 |
| 2003 | 14 |
| 2004 | 21 |
| 2005 | 21 |
| 2006 | 21 |
| 2007 | 34 |
| 2008 | 28 |
| 2009 | 17 |
| 2010 | 23 |
| 2011 | 27 |
| 2012 | 25 |
| 2013 | 31 |
| 2014 | 35 |
| 2015 | 27 |
| 2016 | 62 |
| 2017 | 42 |
| 2018 | 54 |
| 2019 | 64 |
| 2020 | 29 |
| 2021 | 23 |
| 2022 | 29 |
| 2023 | 24 |
| 2024 | 22 |