Year	years
1960	73.1
1961	73.6
1962	73.5
1963	73.4
1964	73.7
1965	73.8
1966	73.9
1967	74.3
1968	74.1
1969	74.4
1970	74.7
1971	75
1972	75.1
1973	75.3
1974	75.9
1975	76.6
1976	76.8
1977	77.2
1978	77.3
1979	77.8
1980	77.4
1981	77.8
1982	78.1
1983	78.1
1984	78.2
1985	78.2
1986	78.2
1987	78.3
1988	78.3
1989	78.5
1990	78.8
1991	78.9
1992	79.1
1993	78.8
1994	79
1995	78.9
1996	79.1
1997	79.4
1998	79.5
1999	79.4
2000	79.3
2001	79.5
2002	79.6
2003	79.7
2004	80.1
2005	80.1
2006	80.3
2007	80.6
2008	80.6
2009	80.9
2010	81
2011	81.1
2012	81.2
2013	81.2
2014	81.3
2015	81.2
2016	81.1
2017	81.1
2018	81.2
2019	81.4
2020	79.9
2021	79.3
2022	80.2