Year	years
1960	75.38
1961	75.85
1962	75.68
1963	75.77
1964	76.26
1965	76.14
1966	76.12
1967	76.57
1968	76.44
1969	76.29
1970	76.5
1971	76.77
1972	76.79
1973	77.13
1974	77.61
1975	77.7
1976	77.92
1977	78.52
1978	78.5
1979	78.92
1980	79.18
1981	79.32
1982	79.41
1983	79.56
1984	79.67
1985	79.66
1986	79.61
1987	80.06
1988	80.24
1989	79.92
1990	80.11
1991	80.15
1992	80.28
1993	80
1994	80.31
1995	80.36
1996	80.35
1997	80.55
1998	80.7
1999	80.5
2000	80.6
2001	80.7
2002	80.7
2003	80.9
2004	81.4
2005	81.6
2006	81.9
2007	82.3
2008	82.3
2009	82.7
2010	82.7
2011	83.1
2012	83
2013	83.2
2014	83.5
2015	83.2
2016	83.2
2017	83.4
2018	83.4
2019	83.7
2020	83.1
2021	83
2022	83.2