Year	years
1960	68.26
1961	68.39
1962	68.45
1963	68.41
1964	68.63
1965	68.76
1966	68.78
1967	68.92
1968	69.09
1969	69.16
1970	69.32
1971	69.6
1972	69.49
1973	69.67
1974	69.74
1975	69.99
1976	70.3
1977	70.64
1978	70.92
1979	71.32
1980	71.59
1981	72.01
1982	72.33
1983	72.68
1984	73.01
1985	73.02
1986	73.22
1987	73.53
1988	73.61
1989	73.92
1990	74.3
1991	74.53
1992	74.76
1993	74.7
1994	74.94
1995	75.07
1996	75.43
1997	75.71
1998	75.97
1999	76.2
2000	76.64
2001	76.92
2002	77.16
2003	77.32
2004	77.68
2005	77.82
2006	78.29
2007	78.29
2008	78.51
2009	78.91
2010	79.21
2011	79.39
2012	79.61
2013	79.74
2014	79.76
2015	79.84
2016	79.92
2017	79.75
2018	79.8
2019	80.18
2020	79.48
2021	79.27
2022	79.12