| Year | Count |
|---|---|
| 1975 | 5 |
| 1976 | 9 |
| 1977 | 22 |
| 1978 | 14 |
| 1979 | 14 |
| 1981 | 5 |
| 1982 | 5 |
| 1983 | 5 |
| 1984 | 6 |
| 1985 | 7 |
| 1986 | 5 |
| 1987 | 5 |
| 1990 | 6 |
| 1991 | 7 |
| 1993 | 8 |
| 1994 | 9 |
| 1995 | 7 |
| 1996 | 8 |
| 1997 | 9 |
| 1998 | 11 |
| 1999 | 12 |
| 2000 | 12 |
| 2001 | 19 |
| 2002 | 10 |
| 2003 | 16 |
| 2004 | 22 |
| 2005 | 33 |
| 2006 | 39 |
| 2007 | 34 |
| 2008 | 57 |
| 2009 | 59 |
| 2010 | 58 |
| 2011 | 65 |
| 2012 | 73 |
| 2013 | 65 |
| 2014 | 68 |
| 2015 | 61 |
| 2016 | 192 |
| 2017 | 216 |
| 2018 | 240 |
| 2019 | 142 |
| 2020 | 156 |
| 2021 | 102 |
| 2022 | 110 |
| 2023 | 120 |
| 2024 | 140 |