Year	years
1960	64.8501613275047
1961	65.07571617992315
1962	64.91580563214384
1963	65.48291300919394
1964	65.96592391968805
1965	65.89986431057912
1966	66.07014964110287
1967	65.86493283525888
1968	65.98950444939206
1969	65.65075876004352
1970	66.25242567568553
1971	66.49909964197208
1972	66.6704467735597
1973	66.80697509816189
1974	66.96502770790258
1975	66.77563765581576
1976	66.7822728114424
1977	66.77743248501476
1978	66.84294300770298
1979	66.79932796914609
1980	66.93328873578953
1981	67.24768313221908
1982	67.57819109481898
1983	67.61987406778513
1984	67.50774726678392
1985	67.86176163085982
1986	68.75268659113758
1987	68.90094934677809
1988	68.92905090054899
1989	69.0190391434566
1990	68.92076367567954
1991	68.64532726311896
1992	67.7704413832955
1993	66.97704662948269
1994	66.9757357434852
1995	67.03153467824269
1996	67.59634247147831
1997	68.08449184203435
1998	68.5068229144103
1999	68.18779046387384
2000	68.38115202503229
2001	68.55774718192971
2002	68.65237877785869
2003	68.77531408036899
2004	69.11397744350892
2005	69.20328913090775
2006	69.78997765157112
2007	70.25576670553184
2008	70.55786461041842
2009	71.10276631229719
2010	71.41672846153013
2011	71.8862088026102
2012	72.25926046136266
2013	72.69385530398057
2014	72.90782852098714
2015	73.12563081178843
2016	73.44179088327978
2017	73.8687404688136
2018	74.0382839699586
2019	74.33362243417602
2020	72.69159816154033
2021	72.01275170760265
2022	73.95449493767248