| Year | Count |
|---|---|
| 1971 | 6 |
| 1973 | 8 |
| 1977 | 8 |
| 1978 | 9 |
| 1979 | 11 |
| 1980 | 10 |
| 1982 | 9 |
| 1984 | 8 |
| 1985 | 5 |
| 1988 | 5 |
| 1992 | 6 |
| 1993 | 5 |
| 1994 | 7 |
| 1995 | 7 |
| 1996 | 11 |
| 1997 | 7 |
| 1998 | 7 |
| 1999 | 6 |
| 2003 | 6 |
| 2004 | 6 |
| 2005 | 5 |
| 2006 | 11 |
| 2008 | 5 |
| 2009 | 14 |
| 2010 | 8 |
| 2011 | 19 |
| 2012 | 14 |
| 2013 | 17 |
| 2014 | 11 |
| 2015 | 13 |
| 2016 | 40 |
| 2017 | 28 |
| 2018 | 38 |
| 2019 | 66 |
| 2020 | 35 |
| 2021 | 36 |
| 2022 | 35 |
| 2023 | 42 |
| 2024 | 37 |