| Year | Count |
|---|---|
| 1972 | 7 |
| 1974 | 9 |
| 1976 | 16 |
| 1977 | 19 |
| 1978 | 20 |
| 1979 | 33 |
| 1980 | 13 |
| 1981 | 49 |
| 1982 | 35 |
| 1983 | 26 |
| 1984 | 33 |
| 1985 | 55 |
| 1986 | 19 |
| 1987 | 33 |
| 1988 | 30 |
| 1989 | 48 |
| 1990 | 51 |
| 1991 | 98 |
| 1992 | 113 |
| 1993 | 125 |
| 1994 | 123 |
| 1995 | 119 |
| 1996 | 186 |
| 1997 | 222 |
| 1998 | 596 |
| 1999 | 356 |
| 2000 | 303 |
| 2001 | 313 |
| 2002 | 228 |
| 2003 | 228 |
| 2004 | 225 |
| 2005 | 151 |
| 2006 | 176 |
| 2007 | 126 |
| 2008 | 104 |
| 2009 | 87 |
| 2010 | 99 |
| 2011 | 104 |
| 2012 | 84 |
| 2013 | 88 |
| 2014 | 58 |
| 2015 | 68 |
| 2016 | 128 |
| 2017 | 123 |
| 2018 | 157 |
| 2019 | 93 |
| 2020 | 123 |
| 2021 | 141 |
| 2022 | 103 |
| 2023 | 120 |
| 2024 | 118 |