| Year | Count |
|---|---|
| 1977 | 5 |
| 1978 | 10 |
| 1979 | 13 |
| 1983 | 6 |
| 1985 | 5 |
| 1988 | 10 |
| 1989 | 5 |
| 1990 | 9 |
| 1991 | 10 |
| 1992 | 29 |
| 1993 | 23 |
| 1994 | 38 |
| 1995 | 44 |
| 1996 | 109 |
| 1997 | 152 |
| 1998 | 139 |
| 1999 | 357 |
| 2000 | 314 |
| 2001 | 365 |
| 2002 | 641 |
| 2003 | 683 |
| 2004 | 658 |
| 2005 | 830 |
| 2006 | 813 |
| 2007 | 708 |
| 2008 | 729 |
| 2009 | 667 |
| 2010 | 579 |
| 2011 | 497 |
| 2012 | 508 |
| 2013 | 538 |
| 2014 | 617 |
| 2015 | 713 |
| 2016 | 861 |
| 2017 | 1,069 |
| 2018 | 1,280 |
| 2019 | 1,293 |
| 2020 | 1,032 |
| 2021 | 1,121 |
| 2022 | 1,052 |
| 2023 | 899 |
| 2024 | 820 |