| Year | Count |
|---|---|
| 1977 | 11 |
| 1978 | 15 |
| 1980 | 14 |
| 1981 | 9 |
| 1983 | 5 |
| 1985 | 6 |
| 1986 | 6 |
| 1987 | 6 |
| 1990 | 5 |
| 1994 | 12 |
| 1995 | 6 |
| 1996 | 29 |
| 1998 | 28 |
| 1999 | 34 |
| 2000 | 22 |
| 2001 | 32 |
| 2002 | 25 |
| 2003 | 47 |
| 2004 | 37 |
| 2005 | 62 |
| 2006 | 67 |
| 2007 | 97 |
| 2008 | 68 |
| 2009 | 117 |
| 2010 | 80 |
| 2011 | 73 |
| 2012 | 57 |
| 2013 | 96 |
| 2014 | 107 |
| 2015 | 124 |
| 2016 | 53 |
| 2017 | 122 |
| 2018 | 59 |
| 2019 | 56 |
| 2020 | 106 |
| 2021 | 105 |
| 2022 | 32 |
| 2023 | 88 |
| 2024 | 64 |