Year	years
1960	46.37345758752565
1961	51.17983007446547
1962	57.623529484267074
1963	58.10079909311271
1964	58.714566523551305
1965	59.237197547361134
1966	59.72325897992228
1967	60.12033977277116
1968	60.513185076346986
1969	60.9287632074369
1970	61.68718880391677
1971	62.34845254188701
1972	62.8566325247493
1973	63.651938655544654
1974	64.29722926253702
1975	64.99292653593477
1976	65.5925482416759
1977	66.23253499063523
1978	66.79206279966837
1979	67.29988183121394
1980	67.80076477823485
1981	68.3187180055327
1982	68.76354819149027
1983	69.15781128514901
1984	69.47828105376193
1985	69.78941597332513
1986	70.26909002237461
1987	70.61061209904105
1988	70.87181079325009
1989	71.14747991624907
1990	71.30618700482825
1991	71.28453408692278
1992	71.60680816222686
1993	72.0052840336349
1994	72.21662396071656
1995	72.51802101133543
1996	72.79935239262457
1997	73.17769789744568
1998	73.69654075454488
1999	73.70072762039504
2000	74.14501493020329
2001	74.8937335976313
2002	75.18557766796489
2003	75.60527809800877
2004	75.913452656041
2005	76.31619170064532
2006	76.69443532619091
2007	77.00368819814547
2008	77.1390014806242
2009	77.54032431274739
2010	77.80800710238852
2011	78.13428182834876
2012	78.42407548845976
2013	78.68776975017455
2014	78.95089274155221
2015	79.17498467398974
2016	79.4615642773146
2017	79.70120656610611
2018	79.96073583062687
2019	80.14803095447616
2020	79.98997169995131
2021	79.54397920685996
2022	80.2033348790335