| Year | Count |
|---|---|
| 1981 | 5 |
| 1984 | 12 |
| 1985 | 5 |
| 1986 | 15 |
| 1987 | 63 |
| 1988 | 57 |
| 1989 | 44 |
| 1990 | 152 |
| 1991 | 269 |
| 1992 | 415 |
| 1993 | 556 |
| 1994 | 640 |
| 1995 | 768 |
| 1996 | 1,116 |
| 1997 | 1,166 |
| 1998 | 1,534 |
| 1999 | 1,573 |
| 2000 | 1,765 |
| 2001 | 1,881 |
| 2002 | 1,812 |
| 2003 | 1,758 |
| 2004 | 2,207 |
| 2004 | 20 |
| 2005 | 2,318 |
| 2006 | 2,405 |
| 2007 | 2,643 |
| 2008 | 2,634 |
| 2009 | 2,225 |
| 2010 | 2,350 |
| 2011 | 2,806 |
| 2012 | 2,673 |
| 2013 | 2,239 |
| 2014 | 2,012 |
| 2015 | 1,839 |
| 2016 | 1,611 |
| 2017 | 1,264 |
| 2018 | 1,105 |
| 2019 | 1,113 |
| 2020 | 930 |
| 2021 | 841 |
| 2022 | 724 |
| 2023 | 634 |
| 2024 | 498 |