Year	years
1960	41.22851361544349
1961	41.65831777539938
1962	42.15808239446765
1963	42.281542495751125
1964	43.00827302676921
1965	42.97901127023983
1966	43.362287267135564
1967	43.96140462897886
1968	44.32376383975462
1969	44.56589027596332
1970	43.24340675606594
1971	40.05736476590682
1972	45.04682880465114
1973	45.62924988423573
1974	45.5668846352835
1975	45.48100041109522
1976	46.100214234500626
1977	46.81774116403479
1978	47.13669061226612
1979	47.62372484480079
1980	48.08729172920325
1981	48.41985177789208
1982	48.706634808747424
1983	47.97907693104825
1984	48.04759896141019
1985	48.41756030325482
1986	49.060653443834354
1987	49.626441242518176
1988	49.441232434131855
1989	50.44195338295231
1990	50.6966756701623
1991	50.41391966504867
1992	51.0674694155414
1993	51.613214740847674
1994	52.29266573095224
1995	52.79980457452746
1996	52.9478056074757
1997	53.654579359858836
1998	53.953939505290926
1999	55.197995509641814
2000	55.7872822922983
2001	56.26721446949184
2002	56.74169501157946
2003	57.324300167460194
2004	57.80399709525775
2005	58.340116794752916
2006	58.938554191481444
2007	59.36777915640925
2008	59.50704061800546
2009	60.49938879160165
2010	60.96005609948409
2011	61.680115018665205
2012	62.25488902627857
2013	62.698315149659024
2014	63.11790889194163
2015	63.49043258103684
2016	64.01452215461406
2017	64.40959625491018
2018	64.81379753488562
2019	65.15100498979167
2020	64.6297215434214
2021	64.21049048576914
2022	64.9225785824994