| Year | Count |
|---|---|
| 1968 | 5 |
| 1969 | 19 |
| 1970 | 6 |
| 1971 | 5 |
| 1972 | 24 |
| 1974 | 8 |
| 1975 | 18 |
| 1976 | 14 |
| 1977 | 22 |
| 1978 | 18 |
| 1979 | 43 |
| 1980 | 16 |
| 1981 | 14 |
| 1982 | 11 |
| 1984 | 24 |
| 1985 | 23 |
| 1986 | 14 |
| 1987 | 35 |
| 1988 | 83 |
| 1989 | 62 |
| 1990 | 91 |
| 1991 | 115 |
| 1992 | 191 |
| 1993 | 202 |
| 1994 | 220 |
| 1995 | 144 |
| 1996 | 168 |
| 1997 | 166 |
| 1998 | 222 |
| 1999 | 130 |
| 2000 | 188 |
| 2001 | 181 |
| 2002 | 162 |
| 2003 | 199 |
| 2004 | 196 |
| 2005 | 195 |
| 2006 | 124 |
| 2007 | 162 |
| 2008 | 149 |
| 2009 | 83 |
| 2010 | 118 |
| 2011 | 124 |
| 2012 | 115 |
| 2013 | 115 |
| 2014 | 135 |
| 2015 | 188 |
| 2016 | 213 |
| 2017 | 186 |
| 2018 | 152 |
| 2019 | 94 |
| 2020 | 157 |
| 2021 | 158 |
| 2022 | 129 |
| 2023 | 81 |
| 2024 | 107 |