| Year | Count |
|---|---|
| 1974 | 8 |
| 1976 | 10 |
| 1977 | 11 |
| 1978 | 15 |
| 1979 | 16 |
| 1980 | 35 |
| 1981 | 29 |
| 1982 | 363 |
| 1983 | 688 |
| 1984 | 877 |
| 1985 | 961 |
| 1986 | 1,005 |
| 1987 | 1,980 |
| 1988 | 2,413 |
| 1989 | 2,927 |
| 1990 | 2,862 |
| 1991 | 3,212 |
| 1992 | 3,281 |
| 1993 | 2,525 |
| 1994 | 2,040 |
| 1995 | 1,682 |
| 1996 | 1,580 |
| 1997 | 1,374 |
| 1998 | 1,106 |
| 1999 | 658 |
| 2000 | 595 |
| 2001 | 573 |
| 2002 | 327 |
| 2003 | 350 |
| 2004 | 405 |
| 2005 | 376 |
| 2006 | 394 |
| 2007 | 423 |
| 2008 | 269 |
| 2009 | 200 |
| 2010 | 158 |
| 2011 | 176 |
| 2012 | 99 |
| 2013 | 91 |
| 2014 | 79 |
| 2015 | 101 |
| 2016 | 53 |
| 2017 | 45 |
| 2018 | 26 |
| 2019 | 36 |
| 2020 | 5 |
| 2021 | 24 |
| 2022 | 16 |
| 2023 | 22 |