Year	scale 1-100
1970	71.25
1971	71.25
1972	71.25
1973	71.25
1974	71.25
1975	71.25
1976	71.25
1977	71.25
1978	71.25
1979	71.25
1980	71.25
1981	71.25
1982	71.25
1983	71.25
1984	71.25
1985	76.25
1986	76.25
1987	76.25
1988	76.25
1989	78.75
1990	78.75
1991	78.75
1992	81.875
1993	81.875
1994	81.875
1995	81.875
1996	81.875
1997	81.875
1998	85
1999	85
2000	91.25
2001	91.25
2002	91.25
2003	91.25
2004	91.25
2005	91.25
2006	91.25
2007	91.25
2008	94.375
2009	97.5
2010	97.5
2011	97.5
2012	100
2013	100
2014	100
2015	100
2016	100
2017	100
2018	100
2019	100
2020	100
2021	100
2022	100
2023	100