| Year | Count |
|---|---|
| 1971 | 7 |
| 1972 | 9 |
| 1977 | 14 |
| 1979 | 14 |
| 1985 | 5 |
| 1987 | 7 |
| 1988 | 9 |
| 1989 | 5 |
| 1990 | 6 |
| 1995 | 9 |
| 1996 | 6 |
| 1997 | 7 |
| 1999 | 9 |
| 2000 | 15 |
| 2001 | 11 |
| 2002 | 14 |
| 2003 | 20 |
| 2004 | 17 |
| 2005 | 29 |
| 2006 | 23 |
| 2007 | 30 |
| 2008 | 28 |
| 2009 | 38 |
| 2010 | 35 |
| 2011 | 46 |
| 2012 | 32 |
| 2013 | 46 |
| 2014 | 25 |
| 2015 | 34 |
| 2016 | 93 |
| 2017 | 129 |
| 2018 | 43 |
| 2019 | 58 |
| 2020 | 88 |
| 2021 | 72 |
| 2022 | 80 |
| 2023 | 74 |
| 2024 | 110 |