Year scale 1-100 1970 51.875 1971 51.875 1972 51.875 1973 51.875 1974 51.875 1975 51.875 1976 51.875 1977 51.875 1978 51.875 1979 51.875 1980 51.875 1981 51.875 1982 51.875 1983 51.875 1984 51.875 1985 51.875 1986 51.875 1987 51.875 1988 51.875 1989 51.875 1990 51.875 1991 51.875 1992 51.875 1993 51.875 1994 51.875 1995 51.875 1996 51.875 1997 51.875 1998 55 1999 63.75 2000 63.75 2001 63.75 2002 63.75 2003 63.75 2004 63.75 2005 63.75 2006 63.75 2007 63.75 2008 75 2009 75 2010 75 2011 75 2012 75 2013 75 2014 75 2015 75 2016 75 2017 75 2018 75 2019 78.125 2020 78.125 2021 78.125 2022 78.125 2023 78.125