| Year | Count |
|---|---|
| 1972 | 45 |
| 1973 | 31 |
| 1974 | 47 |
| 1975 | 84 |
| 1976 | 189 |
| 1977 | 264 |
| 1978 | 201 |
| 1979 | 173 |
| 1980 | 122 |
| 1981 | 115 |
| 1982 | 66 |
| 1983 | 59 |
| 1984 | 44 |
| 1985 | 57 |
| 1986 | 32 |
| 1987 | 40 |
| 1988 | 26 |
| 1989 | 122 |
| 1990 | 113 |
| 1991 | 104 |
| 1992 | 143 |
| 1993 | 51 |
| 1994 | 121 |
| 1995 | 53 |
| 1996 | 83 |
| 1997 | 71 |
| 1998 | 77 |
| 1999 | 23 |
| 2000 | 88 |
| 2001 | 119 |
| 2002 | 58 |
| 2003 | 126 |
| 2004 | 130 |
| 2005 | 244 |
| 2006 | 301 |
| 2007 | 243 |
| 2008 | 297 |
| 2009 | 206 |
| 2010 | 282 |
| 2011 | 290 |
| 2012 | 218 |
| 2013 | 188 |
| 2014 | 173 |
| 2015 | 201 |
| 2016 | 146 |
| 2017 | 138 |
| 2018 | 67 |
| 2019 | 88 |
| 2020 | 48 |
| 2021 | 55 |
| 2022 | 36 |
| 2023 | 36 |
| 2024 | 30 |