Year	years
1960	47.32197722446175
1961	47.81022295720484
1962	48.234905453617976
1963	48.61811590889748
1964	49.14519049799463
1965	48.40762316797666
1966	49.24099004464957
1967	49.95157612506445
1968	50.99409159504085
1969	51.43750870871041
1970	51.38103659630273
1971	51.330100721437574
1972	52.65597132294778
1973	53.16439878030666
1974	53.623524504532924
1975	54.079705447331364
1976	54.68218751053016
1977	55.42070435365022
1978	56.03221461745383
1979	56.71566310001241
1980	57.33628380057951
1981	57.90328815422569
1982	58.46441099113895
1983	58.92542131262256
1984	59.47704129218879
1985	59.984451731715886
1986	60.47763182479639
1987	61.063574897459674
1988	61.531828236325026
1989	61.9483896993435
1990	62.33725983382781
1991	62.645296612888494
1992	63.133587407107974
1993	63.398296315557246
1994	63.614760904826284
1995	64.01050721340292
1996	64.29270215036644
1997	64.76225917262104
1998	65.19062896678273
1999	65.67060514335196
2000	66.03939627006892
2001	66.40014151368757
2002	66.8339549162033
2003	67.19670821459405
2004	67.43435130205351
2005	67.96404014201273
2006	68.46177856311343
2007	68.81293989141146
2008	69.03824627923188
2009	69.57028936948707
2010	69.92468958392668
2011	70.38156844563214
2012	70.8089099653313
2013	71.24155601426564
2014	71.58015210174236
2015	71.93130870835284
2016	72.28013070713384
2017	72.60460306956422
2018	72.87899210832089
2019	73.12684498384388
2020	72.28822658410762
2021	70.7449761741067
2022	71.546203057214