Year scale 1-100 1970 58.75 1971 58.75 1972 58.75 1973 58.75 1974 58.75 1975 58.75 1976 58.75 1977 58.75 1978 58.75 1979 58.75 1980 58.75 1981 58.75 1982 58.75 1983 58.75 1984 58.75 1985 58.75 1986 58.75 1987 58.75 1988 58.75 1989 58.75 1990 58.75 1991 58.75 1992 58.75 1993 58.75 1994 58.75 1995 58.75 1996 58.75 1997 58.75 1998 58.75 1999 58.75 2000 58.75 2001 58.75 2002 58.75 2003 58.75 2004 58.75 2005 58.75 2006 58.75 2007 58.75 2008 58.75 2009 58.75 2010 58.75 2011 58.75 2012 58.75 2013 58.75 2014 58.75 2015 58.75 2016 58.75 2017 58.75 2018 61.25 2019 61.25 2020 61.25 2021 61.25 2022 61.25 2023 61.25