| Year | Count |
|---|---|
| 1979 | 32 |
| 1980 | 91 |
| 1981 | 73 |
| 1982 | 232 |
| 1983 | 191 |
| 1984 | 176 |
| 1985 | 101 |
| 1986 | 161 |
| 1987 | 86 |
| 1988 | 71 |
| 1989 | 100 |
| 1990 | 140 |
| 1991 | 91 |
| 1992 | 89 |
| 1993 | 132 |
| 1994 | 126 |
| 1995 | 96 |
| 1996 | 112 |
| 1997 | 150 |
| 1998 | 300 |
| 1999 | 446 |
| 2000 | 390 |
| 2001 | 386 |
| 2002 | 454 |
| 2003 | 1,324 |
| 2004 | 1,199 |
| 2005 | 983 |
| 2006 | 1,020 |
| 2007 | 1,209 |
| 2008 | 1,251 |
| 2009 | 1,120 |
| 2010 | 1,253 |
| 2011 | 1,956 |
| 2012 | 1,988 |
| 2013 | 1,630 |
| 2014 | 1,386 |
| 2015 | 1,363 |
| 2016 | 1,537 |
| 2017 | 1,377 |
| 2018 | 1,199 |
| 2019 | 1,209 |
| 2020 | 1,047 |
| 2021 | 1,000 |
| 2022 | 941 |
| 2023 | 899 |
| 2024 | 915 |