Year	years
1960	71.92
1961	72.84
1962	72.48
1963	72.65
1964	73.2
1965	72.99
1966	73.37
1967	73.37
1968	73.52
1969	73.27
1970	73.5
1971	73.7
1972	74.1
1973	74.6
1974	74.7
1975	74.7
1976	75.1
1977	75.5
1978	75.7
1979	76
1980	76.1
1981	76.5
1982	76.7
1983	76.7
1984	77.3
1985	77.4
1986	77.8
1987	78.2
1988	78.7
1989	78.8
1990	79
1991	79.1
1992	79.3
1993	79.5
1994	79.8
1995	80.1
1996	80.2
1997	80.7
1998	81
1999	81
2000	81.2
2001	81.7
2002	81.7
2003	81.5
2004	82.1
2005	82.2
2006	82.8
2007	83.1
2008	83.3
2009	83.2
2010	83.5
2011	83.8
2012	83.6
2013	83.8
2014	84
2015	83.7
2016	84.1
2017	84
2018	84.1
2019	84.2
2020	83.6
2021	83.7
2022	83.5