| Year | Count |
|---|---|
| 1971 | 9 |
| 1975 | 5 |
| 1976 | 9 |
| 1977 | 9 |
| 1979 | 5 |
| 1980 | 8 |
| 1981 | 6 |
| 1983 | 7 |
| 1984 | 9 |
| 1986 | 10 |
| 1990 | 6 |
| 1992 | 7 |
| 1994 | 5 |
| 1999 | 10 |
| 2001 | 23 |
| 2003 | 5 |
| 2004 | 5 |
| 2005 | 15 |
| 2006 | 6 |
| 2007 | 11 |
| 2008 | 10 |
| 2009 | 12 |
| 2010 | 10 |
| 2011 | 22 |
| 2012 | 10 |
| 2013 | 6 |
| 2015 | 24 |
| 2016 | 26 |
| 2017 | 20 |
| 2018 | 51 |
| 2019 | 19 |
| 2020 | 9 |
| 2021 | 15 |
| 2022 | 21 |
| 2023 | 10 |