| Year | Count |
|---|---|
| 1969 | 6 |
| 1971 | 5 |
| 1974 | 8 |
| 1975 | 23 |
| 1976 | 12 |
| 1979 | 22 |
| 1981 | 28 |
| 1982 | 46 |
| 1983 | 26 |
| 1984 | 40 |
| 1985 | 78 |
| 1986 | 109 |
| 1987 | 117 |
| 1988 | 165 |
| 1989 | 574 |
| 1990 | 459 |
| 1991 | 717 |
| 1992 | 698 |
| 1993 | 540 |
| 1994 | 686 |
| 1995 | 582 |
| 1996 | 515 |
| 1997 | 619 |
| 1998 | 719 |
| 1999 | 736 |
| 2000 | 652 |
| 2001 | 646 |
| 2002 | 579 |
| 2003 | 715 |
| 2004 | 1,018 |
| 2005 | 1,195 |
| 2006 | 1,360 |
| 2007 | 1,423 |
| 2008 | 1,270 |
| 2009 | 1,056 |
| 2010 | 801 |
| 2011 | 683 |
| 2012 | 514 |
| 2013 | 447 |
| 2014 | 451 |
| 2015 | 457 |
| 2016 | 368 |
| 2017 | 357 |
| 2018 | 264 |
| 2019 | 273 |
| 2020 | 232 |
| 2021 | 263 |
| 2022 | 166 |
| 2023 | 181 |
| 2024 | 206 |