| Year | Count |
|---|---|
| 1964 | 5 |
| 1978 | 7 |
| 1980 | 6 |
| 1981 | 5 |
| 1982 | 12 |
| 1983 | 11 |
| 1984 | 8 |
| 1985 | 5 |
| 1987 | 21 |
| 1988 | 13 |
| 1989 | 17 |
| 1990 | 10 |
| 1991 | 14 |
| 1992 | 20 |
| 1994 | 14 |
| 1995 | 14 |
| 1996 | 23 |
| 1997 | 11 |
| 1998 | 21 |
| 1999 | 26 |
| 2000 | 23 |
| 2001 | 39 |
| 2002 | 30 |
| 2003 | 34 |
| 2004 | 38 |
| 2005 | 39 |
| 2006 | 43 |
| 2007 | 34 |
| 2008 | 54 |
| 2009 | 68 |
| 2010 | 75 |
| 2011 | 53 |
| 2012 | 62 |
| 2013 | 61 |
| 2014 | 39 |
| 2015 | 52 |
| 2016 | 154 |
| 2017 | 130 |
| 2018 | 116 |
| 2019 | 102 |
| 2020 | 37 |
| 2021 | 42 |
| 2022 | 33 |
| 2023 | 44 |
| 2024 | 45 |