| Year | Count |
|---|---|
| 1972 | 6 |
| 1973 | 5 |
| 1974 | 8 |
| 1975 | 6 |
| 1976 | 10 |
| 1977 | 26 |
| 1979 | 8 |
| 1980 | 12 |
| 1981 | 5 |
| 1982 | 6 |
| 1983 | 7 |
| 1984 | 24 |
| 1985 | 12 |
| 1986 | 6 |
| 1987 | 31 |
| 1988 | 13 |
| 1989 | 16 |
| 1990 | 21 |
| 1991 | 36 |
| 1992 | 50 |
| 1993 | 68 |
| 1994 | 55 |
| 1995 | 76 |
| 1996 | 52 |
| 1997 | 136 |
| 1998 | 121 |
| 1999 | 105 |
| 2000 | 163 |
| 2001 | 171 |
| 2002 | 144 |
| 2003 | 143 |
| 2004 | 267 |
| 2005 | 242 |
| 2006 | 276 |
| 2007 | 297 |
| 2008 | 282 |
| 2009 | 228 |
| 2010 | 295 |
| 2011 | 373 |
| 2012 | 440 |
| 2013 | 422 |
| 2014 | 460 |
| 2015 | 528 |
| 2016 | 692 |
| 2017 | 807 |
| 2018 | 633 |
| 2019 | 648 |
| 2020 | 653 |
| 2021 | 646 |
| 2022 | 830 |
| 2023 | 875 |
| 2024 | 921 |