| Year | Count |
|---|---|
| 1964 | 6 |
| 1975 | 5 |
| 1976 | 24 |
| 1977 | 12 |
| 1978 | 6 |
| 1979 | 39 |
| 1980 | 55 |
| 1981 | 39 |
| 1982 | 30 |
| 1983 | 8 |
| 1984 | 31 |
| 1985 | 32 |
| 1986 | 28 |
| 1987 | 47 |
| 1988 | 62 |
| 1989 | 68 |
| 1990 | 80 |
| 1991 | 112 |
| 1992 | 229 |
| 1993 | 165 |
| 1994 | 175 |
| 1995 | 169 |
| 1996 | 232 |
| 1997 | 220 |
| 1998 | 242 |
| 1999 | 314 |
| 2000 | 325 |
| 2001 | 418 |
| 2002 | 394 |
| 2003 | 394 |
| 2004 | 483 |
| 2005 | 581 |
| 2006 | 673 |
| 2007 | 560 |
| 2008 | 678 |
| 2009 | 607 |
| 2010 | 558 |
| 2011 | 491 |
| 2012 | 595 |
| 2013 | 600 |
| 2014 | 503 |
| 2015 | 511 |
| 2016 | 628 |
| 2017 | 5 |
| 2017 | 512 |
| 2018 | 577 |
| 2019 | 649 |
| 2020 | 444 |
| 2021 | 587 |
| 2022 | 489 |
| 2023 | 481 |
| 2024 | 599 |