| Year | Count |
|---|---|
| 1974 | 12 |
| 1976 | 13 |
| 1977 | 6 |
| 1978 | 11 |
| 1979 | 8 |
| 1980 | 25 |
| 1981 | 44 |
| 1982 | 82 |
| 1983 | 68 |
| 1984 | 121 |
| 1985 | 132 |
| 1986 | 196 |
| 1987 | 202 |
| 1988 | 251 |
| 1989 | 177 |
| 1990 | 227 |
| 1991 | 546 |
| 1992 | 639 |
| 1993 | 637 |
| 1994 | 677 |
| 1995 | 665 |
| 1996 | 849 |
| 1997 | 789 |
| 1998 | 903 |
| 1999 | 661 |
| 2000 | 737 |
| 2001 | 679 |
| 2002 | 618 |
| 2003 | 634 |
| 2004 | 772 |
| 2005 | 861 |
| 2006 | 670 |
| 2007 | 718 |
| 2008 | 589 |
| 2009 | 424 |
| 2010 | 382 |
| 2011 | 337 |
| 2012 | 288 |
| 2013 | 275 |
| 2014 | 193 |
| 2015 | 263 |
| 2016 | 126 |
| 2017 | 108 |
| 2018 | 98 |
| 2019 | 89 |
| 2020 | 82 |
| 2021 | 71 |
| 2022 | 15 |
| 2023 | 5 |
| 2024 | 12 |