| Year | Count |
|---|---|
| 1981 | 18 |
| 1982 | 15 |
| 1983 | 13 |
| 1984 | 13 |
| 1985 | 23 |
| 1986 | 70 |
| 1987 | 72 |
| 1988 | 146 |
| 1989 | 88 |
| 1990 | 142 |
| 1991 | 267 |
| 1992 | 382 |
| 1993 | 604 |
| 1994 | 583 |
| 1995 | 656 |
| 1996 | 877 |
| 1997 | 890 |
| 1998 | 1,000 |
| 1999 | 990 |
| 2000 | 1,331 |
| 2001 | 1,326 |
| 2002 | 1,420 |
| 2003 | 1,690 |
| 2004 | 1,837 |
| 2004 | 16 |
| 2005 | 1,928 |
| 2006 | 1,746 |
| 2007 | 1,881 |
| 2008 | 1,798 |
| 2009 | 1,664 |
| 2010 | 1,363 |
| 2011 | 1,470 |
| 2012 | 1,350 |
| 2013 | 1,016 |
| 2014 | 844 |
| 2015 | 774 |
| 2016 | 587 |
| 2017 | 676 |
| 2018 | 386 |
| 2019 | 420 |
| 2020 | 331 |
| 2021 | 286 |
| 2022 | 260 |
| 2023 | 122 |
| 2024 | 117 |