| Year | Count |
|---|---|
| 1967 | 10 |
| 1970 | 8 |
| 1974 | 10 |
| 1975 | 14 |
| 1976 | 34 |
| 1977 | 17 |
| 1978 | 13 |
| 1979 | 66 |
| 1980 | 61 |
| 1981 | 163 |
| 1982 | 167 |
| 1983 | 221 |
| 1984 | 456 |
| 1985 | 388 |
| 1986 | 458 |
| 1987 | 517 |
| 1988 | 542 |
| 1989 | 471 |
| 1990 | 443 |
| 1991 | 526 |
| 1992 | 787 |
| 1993 | 759 |
| 1994 | 605 |
| 1995 | 603 |
| 1996 | 647 |
| 1997 | 692 |
| 1998 | 583 |
| 1999 | 592 |
| 2000 | 585 |
| 2001 | 493 |
| 2002 | 480 |
| 2003 | 460 |
| 2004 | 452 |
| 2005 | 381 |
| 2006 | 400 |
| 2007 | 257 |
| 2008 | 312 |
| 2009 | 282 |
| 2010 | 296 |
| 2011 | 241 |
| 2012 | 199 |
| 2013 | 223 |
| 2014 | 200 |
| 2015 | 184 |
| 2016 | 139 |
| 2017 | 199 |
| 2018 | 173 |
| 2019 | 71 |
| 2020 | 110 |
| 2021 | 108 |
| 2022 | 67 |
| 2023 | 43 |
| 2024 | 60 |