| Year | Count |
|---|---|
| 1964 | 5 |
| 1972 | 6 |
| 1983 | 6 |
| 1988 | 10 |
| 1990 | 6 |
| 1991 | 5 |
| 1993 | 7 |
| 1997 | 10 |
| 1998 | 19 |
| 1999 | 23 |
| 2000 | 33 |
| 2001 | 12 |
| 2002 | 14 |
| 2003 | 20 |
| 2004 | 36 |
| 2005 | 74 |
| 2006 | 62 |
| 2007 | 49 |
| 2008 | 27 |
| 2009 | 45 |
| 2010 | 13 |
| 2011 | 15 |
| 2012 | 14 |
| 2013 | 5 |
| 2014 | 18 |
| 2015 | 32 |
| 2016 | 14 |
| 2017 | 5 |
| 2018 | 5 |
| 2019 | 6 |
| 2020 | 21 |
| 2021 | 17 |
| 2022 | 14 |