| Year | Count |
|---|---|
| 1977 | 5 |
| 1985 | 5 |
| 1990 | 5 |
| 1991 | 5 |
| 1992 | 5 |
| 1994 | 6 |
| 1996 | 6 |
| 1997 | 6 |
| 1998 | 7 |
| 2001 | 6 |
| 2003 | 9 |
| 2004 | 7 |
| 2005 | 9 |
| 2006 | 12 |
| 2007 | 11 |
| 2008 | 13 |
| 2009 | 13 |
| 2010 | 16 |
| 2011 | 19 |
| 2012 | 17 |
| 2013 | 14 |
| 2014 | 26 |
| 2015 | 30 |
| 2016 | 66 |
| 2017 | 52 |
| 2018 | 64 |
| 2019 | 46 |
| 2020 | 19 |
| 2021 | 35 |
| 2022 | 23 |
| 2023 | 19 |
| 2024 | 28 |