| Year | Count |
|---|---|
| 1971 | 6 |
| 1972 | 5 |
| 1977 | 6 |
| 1982 | 5 |
| 1990 | 7 |
| 1991 | 7 |
| 1995 | 6 |
| 1996 | 6 |
| 1997 | 22 |
| 1998 | 8 |
| 1999 | 16 |
| 2000 | 11 |
| 2001 | 7 |
| 2001 | 8 |
| 2003 | 10 |
| 2003 | 5 |
| 2004 | 5 |
| 2005 | 10 |
| 2005 | 16 |
| 2006 | 20 |
| 2006 | 7 |
| 2007 | 9 |
| 2007 | 25 |
| 2008 | 36 |
| 2009 | 12 |
| 2010 | 14 |
| 2011 | 17 |
| 2012 | 29 |
| 2013 | 38 |
| 2014 | 50 |
| 2015 | 64 |
| 2016 | 102 |
| 2017 | 147 |
| 2018 | 140 |
| 2019 | 158 |
| 2020 | 196 |
| 2021 | 196 |
| 2022 | 191 |
| 2023 | 183 |
| 2024 | 172 |