Year	years
1960	54.354835008533804
1961	54.815882558765075
1962	55.34470965174551
1963	55.4664109726752
1964	56.07193049307436
1965	56.750717728834424
1966	57.02656704831662
1967	57.29092673054282
1968	57.5726269345615
1969	57.71775756334559
1970	58.04327735089515
1971	58.30629371796388
1972	58.5803943000824
1973	58.87454238909147
1974	57.68069159899246
1975	58.38664953500481
1976	58.71165609971204
1977	58.946341952017455
1978	59.01721362839091
1979	59.323268941938224
1980	59.86944521106834
1981	60.26895279820195
1982	60.54326050342622
1983	60.73854852895886
1984	61.23421757431165
1985	61.518963248747944
1986	61.82680753655043
1987	62.25958209926855
1988	62.464092906053615
1989	63.249515688741525
1990	63.251633405962195
1991	63.253566118281434
1992	63.308345670157784
1993	63.49903239298995
1994	63.41081220008213
1995	63.43745403786545
1996	63.77583234473481
1997	63.78222253355477
1998	63.786328700184036
1999	63.70525026837974
2000	64.79116827607169
2001	64.98729046662092
2002	65.09075731416875
2003	65.38870946021109
2004	65.65272024425552
2005	66.00272361301023
2006	66.32893895447438
2007	66.67666193346953
2008	67.09709751203587
2009	67.5018377355895
2010	67.95890178676521
2011	68.24789924640919
2012	68.62320326216565
2013	68.96734551328424
2014	69.18905074906975
2015	69.4981063074461
2016	69.8093635707692
2017	70.13398113087047
2018	70.38892468070297
2019	70.52864895733006
2020	70.20831390144447
2021	69.36707394608455
2022	69.89377598300526