| Year | Count |
|---|---|
| 1973 | 10 |
| 1974 | 5 |
| 1975 | 6 |
| 1976 | 16 |
| 1977 | 15 |
| 1978 | 15 |
| 1979 | 18 |
| 1980 | 19 |
| 1981 | 9 |
| 1982 | 7 |
| 1983 | 13 |
| 1984 | 25 |
| 1985 | 13 |
| 1986 | 27 |
| 1987 | 15 |
| 1988 | 51 |
| 1989 | 46 |
| 1990 | 43 |
| 1991 | 60 |
| 1992 | 70 |
| 1993 | 92 |
| 1994 | 100 |
| 1995 | 86 |
| 1996 | 114 |
| 1997 | 143 |
| 1998 | 235 |
| 1999 | 173 |
| 2000 | 215 |
| 2001 | 252 |
| 2002 | 256 |
| 2003 | 350 |
| 2004 | 482 |
| 2005 | 628 |
| 2006 | 630 |
| 2007 | 700 |
| 2008 | 835 |
| 2009 | 672 |
| 2010 | 609 |
| 2011 | 646 |
| 2012 | 692 |
| 2013 | 746 |
| 2014 | 816 |
| 2015 | 964 |
| 2016 | 1,082 |
| 2017 | 1,279 |
| 2018 | 1,299 |
| 2019 | 1,335 |
| 2020 | 1,184 |
| 2021 | 1,643 |
| 2022 | 1,657 |
| 2023 | 2,522 |
| 2024 | 2,561 |