| Year | Count |
|---|---|
| 1975 | 5 |
| 1976 | 7 |
| 1978 | 5 |
| 1979 | 5 |
| 1980 | 5 |
| 1981 | 6 |
| 1982 | 7 |
| 1983 | 9 |
| 1986 | 8 |
| 1987 | 10 |
| 1988 | 19 |
| 1989 | 21 |
| 1990 | 20 |
| 1991 | 22 |
| 1992 | 23 |
| 1993 | 33 |
| 1994 | 33 |
| 1995 | 35 |
| 1996 | 29 |
| 1997 | 35 |
| 1998 | 42 |
| 1999 | 47 |
| 2000 | 32 |
| 2001 | 48 |
| 2002 | 45 |
| 2003 | 55 |
| 2004 | 57 |
| 2005 | 62 |
| 2006 | 74 |
| 2007 | 88 |
| 2008 | 80 |
| 2009 | 101 |
| 2010 | 86 |
| 2011 | 93 |
| 2012 | 92 |
| 2013 | 93 |
| 2014 | 118 |
| 2015 | 119 |
| 2016 | 272 |
| 2017 | 222 |
| 2018 | 212 |
| 2019 | 232 |
| 2020 | 114 |
| 2021 | 94 |
| 2022 | 93 |
| 2023 | 113 |
| 2024 | 72 |