Year scale 1-100 1970 71.25 1971 71.25 1972 71.25 1973 71.25 1974 73.75 1975 73.75 1976 73.75 1977 73.75 1978 73.75 1979 73.75 1980 79.375 1981 79.375 1982 79.375 1983 79.375 1984 79.375 1985 79.375 1986 79.375 1987 79.375 1988 79.375 1989 81.875 1990 81.875 1991 85 1992 87.5 1993 87.5 1994 87.5 1995 87.5 1996 87.5 1997 87.5 1998 87.5 1999 90.625 2000 90.625 2001 90.625 2002 90.625 2003 90.625 2004 90.625 2005 90.625 2006 96.875 2007 96.875 2008 96.875 2009 96.875 2010 96.875 2011 96.875 2012 96.875 2013 100 2014 100 2015 100 2016 100 2017 100 2018 100 2019 100 2020 100 2021 100 2022 100 2023 100