Year	years
1960	41.42254577644811
1961	41.73973935807562
1962	42.20072057552484
1963	42.440620261288736
1964	42.89083772694231
1965	43.029451291311915
1966	42.984090052141084
1967	43.23217833178633
1968	43.67073477598762
1969	43.91130716747808
1970	44.369830237344054
1971	44.87080396884153
1972	44.98734365716508
1973	45.708795356985526
1974	45.920461663804296
1975	46.306432704087854
1976	46.984952204866225
1977	47.447803211481514
1978	47.74858696016245
1979	48.210028914599825
1980	48.57245575503308
1981	48.93781946044994
1982	49.176041684886975
1983	48.33214819239349
1984	48.36180774515386
1985	48.61274752680017
1986	49.00706987375912
1987	49.338121581985504
1988	49.02019767545751
1989	49.88486949339315
1990	49.824307633487955
1991	49.69963102760735
1992	49.472160671427496
1993	49.69693251878119
1994	50.0021598833425
1995	50.11417407159537
1996	50.0485283330994
1997	50.21533670966416
1998	49.927786874302484
1999	50.64083818417793
2000	51.26454480280286
2001	51.53632182500615
2002	51.89134243641399
2003	52.36952152080998
2004	52.84880711910819
2005	53.462195048548054
2006	54.213301069582855
2007	54.84902854487477
2008	55.45071260524644
2009	56.219613071159316
2010	56.84736568908038
2011	57.55861068509845
2012	58.14101324867884
2013	58.668043004745975
2014	59.142658201912674
2015	59.562981700058565
2016	60.069024673119515
2017	60.477138457149515
2018	60.863027538892126
2019	61.244290518923414
2020	60.848894424466415
2021	60.24174346318638
2022	60.76439997752779