| Year | Count |
|---|---|
| 1974 | 5 |
| 1975 | 29 |
| 1977 | 17 |
| 1979 | 40 |
| 1980 | 31 |
| 1981 | 6 |
| 1982 | 6 |
| 1986 | 10 |
| 1988 | 9 |
| 1991 | 5 |
| 1992 | 8 |
| 1993 | 18 |
| 1994 | 105 |
| 1995 | 111 |
| 1996 | 153 |
| 1997 | 305 |
| 1998 | 303 |
| 1999 | 302 |
| 2000 | 408 |
| 2001 | 512 |
| 2002 | 542 |
| 2003 | 596 |
| 2004 | 796 |
| 2005 | 870 |
| 2006 | 971 |
| 2007 | 1,087 |
| 2008 | 1,023 |
| 2009 | 999 |
| 2010 | 1,067 |
| 2011 | 1,191 |
| 2012 | 1,333 |
| 2013 | 1,250 |
| 2014 | 1,151 |
| 2015 | 1,393 |
| 2016 | 1,357 |
| 2017 | 1,490 |
| 2018 | 1,351 |
| 2019 | 1,635 |
| 2020 | 1,291 |
| 2021 | 1,331 |
| 2022 | 1,253 |
| 2023 | 847 |
| 2024 | 771 |