| Year | Count |
|---|---|
| 1974 | 5 |
| 1975 | 7 |
| 1976 | 19 |
| 1977 | 18 |
| 1978 | 22 |
| 1979 | 38 |
| 1980 | 19 |
| 1981 | 27 |
| 1982 | 27 |
| 1983 | 13 |
| 1984 | 17 |
| 1985 | 24 |
| 1986 | 42 |
| 1987 | 38 |
| 1988 | 33 |
| 1989 | 64 |
| 1990 | 80 |
| 1991 | 88 |
| 1992 | 106 |
| 1993 | 67 |
| 1994 | 85 |
| 1995 | 58 |
| 1996 | 69 |
| 1997 | 81 |
| 1998 | 86 |
| 1999 | 77 |
| 2000 | 122 |
| 2001 | 139 |
| 2002 | 114 |
| 2003 | 118 |
| 2004 | 123 |
| 2005 | 113 |
| 2006 | 80 |
| 2007 | 100 |
| 2008 | 126 |
| 2009 | 117 |
| 2010 | 92 |
| 2011 | 130 |
| 2012 | 132 |
| 2013 | 124 |
| 2014 | 117 |
| 2015 | 146 |
| 2016 | 182 |
| 2017 | 155 |
| 2018 | 190 |
| 2019 | 121 |
| 2020 | 106 |
| 2021 | 131 |
| 2022 | 125 |
| 2023 | 123 |
| 2024 | 141 |