Year	years
1960	55.46653658536586
1961	56.5219756097561
1962	57.49129268292683
1963	58.353219512195125
1964	59.14
1965	59.567853658536585
1966	59.15019512195123
1967	58.320536585365865
1968	58.66680487804879
1969	59.85500000000001
1970	61.000365853658536
1971	60.9889756097561
1972	60.73346341463415
1973	61.05670731707318
1974	61.64375609756098
1975	62.355804878048794
1976	62.86678048780489
1977	63.76209756097561
1978	64.5939268292683
1979	65.30643902439024
1980	65.81648780487805
1981	66.5479512195122
1982	67.03475609756097
1983	67.28563414634148
1984	67.3439024390244
1985	67.49063414634146
1986	67.77104878048782
1987	68.09697560975611
1988	68.36121951219515
1989	68.95
1990	69.40487804878049
1991	69.95609756097562
1992	70.05853658536586
1993	70.10731707317075
1994	70.15853658536585
1995	70.3258536585366
1996	70.3229268292683
1997	70.40487804878049
1998	70.60731707317073
1999	70.96097560975612
2000	71.66341463414635
2001	71.7658536585366
2002	71.96585365853659
2003	72.1170731707317
2004	72.2658536585366
2005	72.43219512195122
2006	72.43219512195122
2007	72.57073170731708
2008	72.57073170731708
2009	72.88243902439025
2010	72.96731707317073
2011	73.2668292682927
2012	73.86341463414635
2013	74.01707317073172
2014	74.19439024390245
2015	74.35317073170732
2016	74.3948780487805
2017	74.51463414634146
2018	74.41634146341464
2019	74.23585365853658
2020	74.1770731707317
2021	73.68024390243903
2022	73.51463414634146