| Year | Count |
|---|---|
| 1958 | 18 |
| 1959 | 12 |
| 1960 | 13 |
| 1963 | 5 |
| 1971 | 7 |
| 1973 | 5 |
| 1977 | 8 |
| 1978 | 8 |
| 1986 | 5 |
| 1987 | 6 |
| 1989 | 5 |
| 1990 | 5 |
| 1991 | 6 |
| 1994 | 5 |
| 1995 | 6 |
| 1996 | 7 |
| 1997 | 6 |
| 1998 | 14 |
| 2000 | 10 |
| 2001 | 9 |
| 2002 | 8 |
| 2003 | 8 |
| 2004 | 6 |
| 2005 | 6 |
| 2006 | 13 |
| 2007 | 12 |
| 2008 | 8 |
| 2009 | 12 |
| 2010 | 9 |
| 2012 | 9 |
| 2013 | 22 |
| 2014 | 18 |
| 2015 | 20 |
| 2016 | 32 |
| 2017 | 32 |
| 2018 | 26 |
| 2019 | 36 |
| 2020 | 12 |
| 2021 | 19 |
| 2022 | 9 |
| 2023 | 11 |
| 2024 | 11 |