| Year | Count |
|---|---|
| 1959 | 10 |
| 1973 | 5 |
| 1979 | 10 |
| 1981 | 12 |
| 1984 | 6 |
| 1985 | 6 |
| 1987 | 7 |
| 1988 | 7 |
| 1989 | 6 |
| 1990 | 6 |
| 1991 | 6 |
| 1992 | 7 |
| 1993 | 21 |
| 1994 | 23 |
| 1995 | 33 |
| 1996 | 41 |
| 1997 | 22 |
| 1998 | 77 |
| 1999 | 19 |
| 2000 | 47 |
| 2001 | 82 |
| 2002 | 93 |
| 2003 | 83 |
| 2004 | 166 |
| 2005 | 188 |
| 2006 | 146 |
| 2007 | 192 |
| 2008 | 216 |
| 2009 | 132 |
| 2010 | 244 |
| 2011 | 143 |
| 2012 | 167 |
| 2013 | 75 |
| 2014 | 40 |
| 2015 | 114 |
| 2016 | 71 |
| 2017 | 97 |
| 2018 | 70 |
| 2019 | 80 |
| 2020 | 76 |
| 2021 | 59 |
| 2022 | 59 |
| 2023 | 113 |
| 2024 | 70 |