| Year | Count |
|---|---|
| 1977 | 5 |
| 1978 | 5 |
| 1979 | 5 |
| 1980 | 12 |
| 1981 | 5 |
| 1982 | 16 |
| 1983 | 19 |
| 1984 | 40 |
| 1985 | 90 |
| 1986 | 53 |
| 1987 | 46 |
| 1988 | 77 |
| 1989 | 68 |
| 1990 | 132 |
| 1991 | 174 |
| 1992 | 180 |
| 1993 | 121 |
| 1994 | 147 |
| 1995 | 194 |
| 1996 | 160 |
| 1997 | 216 |
| 1998 | 237 |
| 1999 | 191 |
| 2000 | 273 |
| 2001 | 322 |
| 2002 | 328 |
| 2003 | 455 |
| 2004 | 461 |
| 2005 | 680 |
| 2006 | 930 |
| 2007 | 1,379 |
| 2008 | 1,527 |
| 2009 | 1,283 |
| 2010 | 1,583 |
| 2011 | 3,600 |
| 2012 | 4,861 |
| 2013 | 5,048 |
| 2014 | 4,695 |
| 2015 | 4,283 |
| 2016 | 4,148 |
| 2017 | 4,080 |
| 2018 | 3,221 |
| 2019 | 2,726 |
| 2020 | 1,902 |
| 2021 | 1,794 |
| 2022 | 1,525 |
| 2023 | 1,276 |
| 2024 | 896 |