Year	years
1960	52.949651843018216
1961	54.946327612741264
1962	57.3629842626739
1963	57.71068704569874
1964	58.219741914877346
1965	58.15301238769927
1966	58.622271129460984
1967	59.04553446096459
1968	59.498492636852006
1969	59.7958591346196
1970	60.087370817223665
1971	60.3824274474329
1972	61.0333092142879
1973	61.5316483230467
1974	61.98339928469561
1975	62.44776923268744
1976	62.910572850815456
1977	63.47390459373493
1978	63.88749736092763
1979	64.34713378156276
1980	64.70552844403994
1981	65.13172574734496
1982	65.5138899042461
1983	65.76049161109151
1984	66.06304438443478
1985	66.32439064076415
1986	66.70778678807385
1987	67.0256466497585
1988	67.22456705957775
1989	67.54161574068003
1990	67.72864522231437
1991	67.79961040930105
1992	68.0734080558691
1993	68.29248672711682
1994	68.50315165792078
1995	68.68695768359453
1996	68.89603923137375
1997	69.22412230425064
1998	69.52647807672489
1999	69.76310755697689
2000	70.08523424055933
2001	70.50714686030567
2002	70.78025812143699
2003	71.07341046186579
2004	71.32939889700693
2005	71.69251493948005
2006	72.08557106817719
2007	72.36906233806909
2008	72.51750846476557
2009	72.9297700942339
2010	73.19098388244878
2011	73.53382454846705
2012	73.82146321596497
2013	74.11990321048508
2014	74.38630455110973
2015	74.57274073285166
2016	74.83748426552174
2017	75.0623568152852
2018	75.27126321507919
2019	75.46961905626038
2020	74.85714392470472
2021	73.93455694913317
2022	74.53352770304711