| Year | Count |
|---|---|
| 1978 | 11 |
| 1979 | 50 |
| 1980 | 65 |
| 1981 | 119 |
| 1982 | 208 |
| 1983 | 226 |
| 1984 | 121 |
| 1985 | 140 |
| 1986 | 123 |
| 1987 | 290 |
| 1988 | 517 |
| 1989 | 502 |
| 1990 | 478 |
| 1991 | 487 |
| 1992 | 448 |
| 1993 | 422 |
| 1994 | 341 |
| 1995 | 318 |
| 1996 | 262 |
| 1997 | 189 |
| 1998 | 213 |
| 1999 | 182 |
| 2000 | 237 |
| 2001 | 285 |
| 2002 | 186 |
| 2003 | 216 |
| 2004 | 142 |
| 2005 | 173 |
| 2006 | 188 |
| 2007 | 198 |
| 2008 | 213 |
| 2009 | 167 |
| 2010 | 142 |
| 2011 | 121 |
| 2012 | 91 |
| 2013 | 71 |
| 2014 | 86 |
| 2015 | 103 |
| 2016 | 100 |
| 2017 | 102 |
| 2018 | 55 |
| 2019 | 26 |
| 2020 | 19 |
| 2021 | 25 |
| 2022 | 33 |
| 2023 | 6 |
| 2024 | 12 |