Year	years
1960	66.94
1961	66.81
1962	65.91
1963	66.78
1964	68.27
1965	68.13
1966	68.13
1967	67.96
1968	67.66
1969	67.07
1970	66.78
1971	67.55
1972	66.81
1973	67.22
1974	67.01
1975	66.36
1976	66.28
1977	66.19
1978	65.99
1979	65.57
1980	65.57
1981	65.49
1982	65.91
1983	65.89
1984	65.32
1985	65.75
1986	67.91
1987	67.72
1988	67.45
1989	66.84
1990	66.39
1991	65.13
1992	64.81
1993	63.13
1994	62.54
1995	63.26
1996	64.63
1997	65.47
1998	66
1999	66.4
2000	66.8
2001	66
2002	66.2
2003	66.5
2004	66.4
2005	65.4
2006	65.3
2007	64.9
2008	66.3
2009	67.5
2010	68
2011	68.1
2012	68.4
2013	68.5
2014	69.2
2015	69.2
2016	69.5
2017	70.7
2018	70.9
2019	71.6
2020	70.1
2021	69.5
2022	71.5