Year	years
1960	72.526
1961	73.017
1962	72.652
1963	73.199
1964	73.482
1965	72.786
1966	73.173
1967	73.757
1968	73.45
1969	73.055
1970	72.922
1971	73.262
1972	73.838
1973	73.407
1974	73.699
1975	73.936
1976	74.088
1977	74.282
1978	74.125
1979	74.557
1980	74.25
1981	74.65
1982	74.72
1983	74.51
1984	74.91
1985	74.74
1986	74.75
1987	75.13
1988	75.5
1989	75.38
1990	75.44
1991	75.17
1992	76.2
1993	76.7
1994	76.5
1995	76.3
1996	76.7
1997	76.7
1998	76.7
1999	77
2000	77.2
2001	77.5
2002	77.6
2003	77.6
2004	77.8
2005	77.9
2006	78.2
2007	78.1
2008	78.7
2009	78.7
2010	78.8
2011	79.8
2012	79.9
2013	80.1
2014	80.5
2015	80.2
2016	80.7
2017	80.7
2018	80.8
2019	81.2
2020	80.4
2021	78.2
2022	80.6