Year	years
1960	67.55
1961	68.42
1962	67.77
1963	68.68
1964	69.37
1965	69.45
1966	69.36
1967	68.37
1968	69.23
1969	68.23
1970	69.11
1971	68.62
1972	68.68
1973	69.03
1974	68.93
1975	68.64
1976	68.99
1977	68.26
1978	68.77
1979	68.64
1980	68.46
1981	68.85
1982	68.43
1983	68.44
1984	68.49
1985	68.15
1986	68.56
1987	68.4
1988	68.38
1989	68.42
1990	68.3
1991	68.4
1992	68.07
1993	67.62
1994	67.36
1995	67.39
1996	67.39
1997	67
1998	67.5
1999	67.9
2000	68.2
2001	68.5
2002	68.5
2003	68.7
2004	69.1
2005	69
2006	69.1
2007	69.2
2008	69.5
2009	69.9
2010	70
2011	70.7
2012	70.9
2013	71.3
2014	71.1
2015	71.2
2016	71.3
2017	71.4
2018	71.5
2019	71.6
2020	70
2021	68
2022	70.8