Year	years
1960	39.376250599680674
1961	45.20718006718458
1962	53.31996034227212
1963	53.82919671262991
1964	54.569125021412866
1965	54.78350401881
1966	55.70454724199882
1967	56.545753575359896
1968	57.04690620016098
1969	57.722922725442444
1970	58.46281207682142
1971	59.255597583899316
1972	59.89258441196023
1973	60.86162532381647
1974	61.60777220190705
1975	62.32480364654315
1976	63.127873710654455
1977	63.93146058481498
1978	64.62313040300029
1979	65.24922847813245
1980	65.81446121347369
1981	66.31203719381102
1982	66.80764039537233
1983	67.26372078082503
1984	67.6454633113295
1985	68.03224920831438
1986	68.42639628638716
1987	68.7816553093269
1988	69.08793703757463
1989	69.41135307045693
1990	69.58480696906591
1991	69.62561708801285
1992	70.20467168255324
1993	70.79540561650185
1994	70.95949125309095
1995	71.31875283877268
1996	71.53326792092871
1997	71.92048806616992
1998	72.44318526378952
1999	72.50789629928889
2000	72.94080941963041
2001	73.78833126692479
2002	74.11038787498252
2003	74.62066692318474
2004	74.63694118089929
2005	75.21381625395553
2006	75.56193783954814
2007	75.83352409978626
2008	75.70879957065769
2009	76.35377946549856
2010	76.5579366305986
2011	76.84082130478642
2012	77.12717668789544
2013	77.39731403829848
2014	77.6482155300053
2015	77.88193296517812
2016	78.12324971631523
2017	78.34046234440669
2018	78.65327900000831
2019	78.82335308356376
2020	78.84336810718388
2021	78.44554130796257
2022	78.9512388518687