| Year | Count |
|---|---|
| 1971 | 11 |
| 1972 | 5 |
| 1973 | 6 |
| 1974 | 5 |
| 1975 | 11 |
| 1976 | 8 |
| 1979 | 5 |
| 1981 | 5 |
| 1985 | 6 |
| 1988 | 6 |
| 1989 | 6 |
| 1992 | 8 |
| 1997 | 5 |
| 1999 | 5 |
| 2004 | 6 |
| 2005 | 8 |
| 2006 | 5 |
| 2007 | 5 |
| 2008 | 18 |
| 2009 | 15 |
| 2010 | 16 |
| 2011 | 10 |
| 2013 | 16 |
| 2014 | 5 |
| 2016 | 7 |
| 2017 | 24 |
| 2018 | 35 |
| 2019 | 6 |
| 2020 | 6 |
| 2021 | 5 |
| 2022 | 27 |
| 2023 | 34 |
| 2024 | 17 |