| Year | Count |
|---|---|
| 1979 | 27 |
| 1981 | 10 |
| 1982 | 5 |
| 1983 | 5 |
| 1985 | 5 |
| 1989 | 7 |
| 1990 | 5 |
| 1992 | 10 |
| 1996 | 5 |
| 1998 | 21 |
| 1999 | 36 |
| 2000 | 55 |
| 2001 | 59 |
| 2002 | 33 |
| 2003 | 60 |
| 2004 | 91 |
| 2005 | 119 |
| 2006 | 129 |
| 2007 | 52 |
| 2008 | 10 |
| 2008 | 146 |
| 2009 | 138 |
| 2010 | 133 |
| 2011 | 62 |
| 2012 | 85 |
| 2013 | 68 |
| 2014 | 49 |
| 2015 | 41 |
| 2016 | 28 |
| 2017 | 19 |
| 2018 | 7 |
| 2019 | 6 |
| 2022 | 6 |
| 2023 | 8 |
| 2024 | 6 |