| Year | Count |
|---|---|
| 1975 | 15 |
| 1976 | 10 |
| 1977 | 5 |
| 1979 | 5 |
| 1981 | 46 |
| 1982 | 62 |
| 1983 | 50 |
| 1984 | 65 |
| 1985 | 94 |
| 1986 | 119 |
| 1987 | 122 |
| 1988 | 120 |
| 1989 | 112 |
| 1990 | 120 |
| 1991 | 254 |
| 1992 | 284 |
| 1993 | 278 |
| 1994 | 334 |
| 1995 | 297 |
| 1996 | 389 |
| 1997 | 355 |
| 1998 | 342 |
| 1999 | 281 |
| 2000 | 283 |
| 2001 | 287 |
| 2002 | 193 |
| 2003 | 263 |
| 2004 | 296 |
| 2005 | 280 |
| 2006 | 282 |
| 2007 | 208 |
| 2008 | 293 |
| 2009 | 126 |
| 2010 | 170 |
| 2011 | 135 |
| 2012 | 108 |
| 2013 | 85 |
| 2014 | 49 |
| 2015 | 98 |
| 2016 | 94 |
| 2017 | 66 |
| 2018 | 47 |
| 2019 | 33 |
| 2020 | 107 |
| 2021 | 11 |
| 2022 | 10 |
| 2023 | 15 |
| 2024 | 10 |