Number of
CV-observers per year
1981 3
1982 3
1983 2
1984 3
1985 2
1986 8
1987 15
1988 14
1989 13
1990 10
1991 11
1992 16
1993 13
1994 19
1995 19
1996 24
1997 26
1998 39
1999 45
2000 49
2001 47
2002 48
2003 52
2004 52
2005 48
2006 47
2007 51
2008 52
2009 49
2010 48
2011 43
2012 39
2013 35
2014 37
2015 37
2016 38
2017 38
2018 45
2019 48
2020 49
2021 49
2022 43
2023 38
2024 27
2025