| Year | Count |
|---|---|
| 1981 | 7 |
| 1984 | 6 |
| 1985 | 18 |
| 1986 | 30 |
| 1987 | 45 |
| 1988 | 129 |
| 1989 | 123 |
| 1990 | 145 |
| 1991 | 359 |
| 1992 | 352 |
| 1993 | 522 |
| 1994 | 629 |
| 1995 | 844 |
| 1996 | 987 |
| 1997 | 993 |
| 1998 | 1,221 |
| 1999 | 1,056 |
| 2000 | 999 |
| 2001 | 828 |
| 2002 | 528 |
| 2003 | 665 |
| 2004 | 674 |
| 2005 | 734 |
| 2006 | 646 |
| 2007 | 596 |
| 2008 | 589 |
| 2009 | 486 |
| 2010 | 409 |
| 2011 | 423 |
| 2012 | 375 |
| 2013 | 264 |
| 2014 | 199 |
| 2015 | 212 |
| 2016 | 132 |
| 2017 | 184 |
| 2018 | 94 |
| 2019 | 88 |
| 2020 | 86 |
| 2021 | 53 |
| 2022 | 49 |
| 2023 | 32 |
| 2024 | 19 |