| Year | Count |
|---|---|
| 1977 | 10 |
| 1978 | 514 |
| 1979 | 346 |
| 1980 | 268 |
| 1981 | 194 |
| 1982 | 203 |
| 1983 | 198 |
| 1984 | 146 |
| 1985 | 84 |
| 1986 | 137 |
| 1987 | 117 |
| 1988 | 158 |
| 1989 | 148 |
| 1990 | 195 |
| 1991 | 186 |
| 1992 | 189 |
| 1993 | 201 |
| 1994 | 212 |
| 1995 | 225 |
| 1996 | 252 |
| 1997 | 170 |
| 1998 | 169 |
| 1999 | 168 |
| 2000 | 210 |
| 2001 | 191 |
| 2002 | 150 |
| 2003 | 174 |
| 2004 | 192 |
| 2005 | 135 |
| 2006 | 140 |
| 2007 | 152 |
| 2008 | 106 |
| 2009 | 106 |
| 2010 | 131 |
| 2011 | 123 |
| 2012 | 68 |
| 2013 | 32 |
| 2014 | 34 |
| 2015 | 29 |
| 2016 | 20 |
| 2017 | 92 |
| 2018 | 43 |
| 2019 | 18 |
| 2020 | 54 |
| 2021 | 44 |
| 2022 | 27 |
| 2023 | 30 |
| 2024 | 43 |