| Year | Count |
|---|---|
| 1975 | 14 |
| 1976 | 32 |
| 1977 | 56 |
| 1978 | 103 |
| 1979 | 211 |
| 1980 | 206 |
| 1981 | 168 |
| 1982 | 211 |
| 1983 | 237 |
| 1984 | 216 |
| 1985 | 259 |
| 1986 | 292 |
| 1987 | 307 |
| 1988 | 380 |
| 1989 | 382 |
| 1990 | 235 |
| 1991 | 233 |
| 1992 | 223 |
| 1993 | 170 |
| 1994 | 133 |
| 1995 | 87 |
| 1996 | 96 |
| 1997 | 106 |
| 1998 | 91 |
| 1999 | 59 |
| 2000 | 38 |
| 2001 | 83 |
| 2002 | 74 |
| 2003 | 117 |
| 2004 | 120 |
| 2005 | 133 |
| 2006 | 107 |
| 2007 | 99 |
| 2008 | 142 |
| 2009 | 63 |
| 2010 | 113 |
| 2011 | 117 |
| 2012 | 91 |
| 2013 | 92 |
| 2014 | 62 |
| 2015 | 32 |
| 2016 | 45 |
| 2017 | 33 |
| 2018 | 45 |
| 2020 | 30 |
| 2021 | 15 |
| 2022 | 28 |
| 2023 | 10 |
| 2024 | 20 |