Year	years
1960	72.9
1961	73.56
1962	72.44
1963	73.8
1964	74.91
1965	74.68
1966	75.08
1967	75.43
1968	75.15
1969	74.98
1970	75.03
1971	76.13
1972	75.45
1973	75.65
1974	75.69
1975	75.6
1976	75.87
1977	75.66
1978	75.45
1979	75.64
1980	75.64
1981	75.68
1982	76.01
1983	75.91
1984	75.57
1985	75.49
1986	76.46
1987	76.36
1988	76.29
1989	76.24
1990	76.17
1991	75.86
1992	75.93
1993	74.98
1994	74.82
1995	75.04
1996	75.86
1997	76.62
1998	76.7
1999	77
2000	77.5
2001	77.6
2002	77.6
2003	77.9
2004	77.8
2005	77.4
2006	77.1
2007	77.2
2008	77.6
2009	78.6
2010	78.8
2011	79.3
2012	79.6
2013	79.6
2014	80.1
2015	79.7
2016	80.1
2017	80.5
2018	80.7
2019	81.2
2020	80.1
2021	78.8
2022	80.3