Year	years
1960	39.936486093579084
1961	40.19358292411599
1962	40.75615612397444
1963	40.92132714231309
1964	41.33880116619938
1965	41.471011409072894
1966	41.470090133684124
1967	41.56334730828552
1968	42.010892654183834
1969	42.248357847763934
1970	42.804827774353946
1971	43.29687498558809
1972	43.41732319166781
1973	44.211278705831134
1974	44.43248112988704
1975	44.817958491903894
1976	45.405262947701054
1977	45.807338130189784
1978	46.024703404197346
1979	46.5120971018203
1980	46.88373130213431
1981	47.22347877827711
1982	47.433636057279735
1983	46.58913154514721
1984	46.523234345850724
1985	46.75368631531391
1986	47.12415713823102
1987	47.33626738834285
1988	46.998559426373305
1989	47.93043182867709
1990	47.79775987291264
1991	47.746964067713606
1992	47.500252054098915
1993	47.7004039847874
1994	48.171677255328504
1995	48.2531130780926
1996	48.207112631754576
1997	48.42095219621785
1998	48.09347554728754
1999	48.87103536639768
2000	49.76667094571204
2001	50.12352093417093
2002	50.48915625930067
2003	51.01322919947332
2004	51.51093555422513
2005	52.11547430633518
2006	52.869201559909236
2007	53.46304769464436
2008	54.04304501344874
2009	54.72921512190718
2010	55.3262066424181
2011	55.967547393212385
2012	56.49453588915654
2013	56.94217539837116
2014	57.36744372358984
2015	57.76649486801431
2016	58.262184315743106
2017	58.657879819470786
2018	59.01098213503432
2019	59.364417392891276
2020	58.90287981044087
2021	58.26433575250977
2022	58.807849649292166