Year	years
1960	43.015638094803016
1961	43.395855642490226
1962	43.71042067301691
1963	44.03557896543022
1964	44.51702832078212
1965	44.66610037670681
1966	44.578624746593
1967	44.997421050913346
1968	45.42200965710934
1969	45.66602412237998
1970	46.01550591426388
1971	46.52411588552484
1972	46.64124512912265
1973	47.27646337253259
1974	47.48160371662698
1975	47.866939979689555
1976	48.64620120757336
1977	49.17471748092111
1978	49.57450800691291
1979	50.00245350269365
1980	50.361478168037564
1981	50.75817771969595
1982	51.024382330516595
1983	50.17979427706145
1984	50.31086792103257
1985	50.56753703756917
1986	50.972288723050546
1987	51.45543986346639
1988	51.179517247542975
1989	51.91436095368729
1990	51.9386221606848
1991	51.72054745552808
1992	51.52909661874794
1993	51.78047067402533
1994	51.88123399206714
1995	52.017043317114464
1996	51.9253884369714
1997	52.03460216120838
1998	51.815262932911324
1999	52.445727340145766
2000	52.75532892273488
2001	52.9376286036268
2002	53.27886442691207
2003	53.708367215000195
2004	54.16860796641823
2005	54.78910530638716
2006	55.53382813310289
2007	56.21490339189118
2008	56.83912781750121
2009	57.696470539416474
2010	58.3555934116389
2011	59.14174882601447
2012	59.78255972674616
2013	60.39725815333863
2014	60.92525982637782
2015	61.36889509231488
2016	61.888234052796975
2017	62.30683474221162
2018	62.72966203872528
2019	63.138905950894475
2020	62.83038483495726
2021	62.27822957939876
2022	62.77290872255058