Year	years
1960	38.43918119576909
1961	38.656089938183875
1962	39.29319711336999
1963	39.499198512212274
1964	39.92010379386383
1965	40.06847202967326
1966	40.34743582935125
1967	40.236628949039456
1968	40.77434259523041
1969	41.06942742800875
1970	41.75708496540644
1971	42.37924818476839
1972	42.6771168097998
1973	43.63989516255164
1974	44.03253762037
1975	44.49013412079326
1976	45.08024018139651
1977	45.57256384307705
1978	45.77036312742432
1979	46.10182315767928
1980	46.087302904861154
1981	46.263731611483536
1982	46.38261703925455
1983	46.11778476696947
1984	45.75854663066769
1985	45.90329537262772
1986	46.452666397170674
1987	45.88808285618215
1988	45.44836792595315
1989	46.77737398781511
1990	46.772568093732595
1991	46.788764469119364
1992	46.689567860648765
1993	47.17711657940453
1994	48.16125562193222
1995	47.95471585103401
1996	47.95714906924785
1997	48.249585766519196
1998	47.83778653886522
1999	49.005259558798286
2000	49.95038709749698
2001	50.42785012126221
2002	50.90966230831419
2003	51.41012044123923
2004	51.87138084354677
2005	52.468662104280085
2006	53.093699796811066
2007	53.60031740377407
2008	54.195745849748015
2009	54.90396768617025
2010	55.38120893699397
2011	55.92194437780519
2012	56.38005942625985
2013	56.773856982813484
2014	57.15458169915479
2015	57.525862238707894
2016	57.90489880072997
2017	58.272973900141814
2018	58.69631993877266
2019	59.03332120670241
2020	58.490235060487095
2021	58.06590375486083
2022	58.71103154477008