Year	years
1960	39.52486452423052
1961	39.81932654883704
1962	40.15402943129482
1963	40.1900205531313
1964	40.84428814439627
1965	40.879238605140074
1966	40.772468553991025
1967	41.49178780566902
1968	41.899556164453294
1969	42.187364026114835
1970	42.53610126559055
1971	42.99158702794091
1972	42.78615725194991
1973	43.57507414085003
1974	43.74317113458109
1975	44.04163709231172
1976	44.67585584487867
1977	45.00013121197586
1978	45.138633265164536
1979	45.57132110382101
1980	45.87218620229272
1981	46.061056183363256
1982	46.01746716362071
1983	44.831100957168324
1984	44.45932038010302
1985	44.91185030790243
1986	45.66603305410158
1987	46.310667623625214
1988	45.86697121915612
1989	47.57623211271387
1990	47.52229662631047
1991	47.66987062717412
1992	47.562385735742346
1993	48.362406225553485
1994	49.285681357999984
1995	49.01602187803718
1996	49.14050671345466
1997	49.62459278199646
1998	48.95530367140384
1999	50.28153586788952
2000	51.59850476243252
2001	52.16260106572448
2002	52.64555710236846
2003	53.7028217001845
2004	54.19273732689061
2005	54.73949799268077
2006	55.597593706641184
2007	56.22275559105447
2008	56.77221011939302
2009	57.3987193575234
2010	57.908371294273216
2011	58.43906944488806
2012	58.57987051434331
2013	58.824126322009995
2014	59.188017755797155
2015	59.527784202392105
2016	59.9783370835827
2017	60.35277941021012
2018	60.62415637015239
2019	61.08694254227801
2020	60.61399521100687
2021	60.05085589167153
2022	60.55135654032704