| Year | Count |
|---|---|
| 1964 | 5 |
| 1978 | 7 |
| 1979 | 5 |
| 1980 | 6 |
| 1981 | 11 |
| 1982 | 12 |
| 1983 | 11 |
| 1984 | 20 |
| 1985 | 5 |
| 1987 | 35 |
| 1988 | 34 |
| 1989 | 42 |
| 1990 | 16 |
| 1991 | 29 |
| 1992 | 31 |
| 1993 | 9 |
| 1994 | 41 |
| 1995 | 42 |
| 1996 | 53 |
| 1997 | 66 |
| 1998 | 99 |
| 1999 | 134 |
| 2000 | 124 |
| 2001 | 305 |
| 2002 | 305 |
| 2003 | 268 |
| 2004 | 346 |
| 2005 | 388 |
| 2006 | 458 |
| 2007 | 418 |
| 2008 | 569 |
| 2009 | 507 |
| 2010 | 571 |
| 2011 | 472 |
| 2012 | 622 |
| 2013 | 540 |
| 2014 | 495 |
| 2015 | 583 |
| 2016 | 809 |
| 2017 | 651 |
| 2018 | 549 |
| 2019 | 556 |
| 2020 | 363 |
| 2021 | 485 |
| 2022 | 470 |
| 2023 | 515 |
| 2024 | 533 |