Year	years
1960	41.999325391616466
1961	42.500036713077876
1962	43.164303678190464
1963	43.44903873747101
1964	44.07100770758871
1965	44.25626754397945
1966	44.754790340294804
1967	45.06763205394497
1968	45.581637080131046
1969	45.922884594601676
1970	45.532468357446845
1971	42.20532751071847
1972	46.88733192271881
1973	47.41108834358728
1974	47.552105321613844
1975	47.79574854693937
1976	48.33934173116746
1977	48.80434412778062
1978	49.07004954702507
1979	49.44361408702489
1980	49.964907373132554
1981	50.307741243286344
1982	50.466679575287166
1983	50.27658460261292
1984	50.306911480611575
1985	50.586441489609314
1986	51.02965875694078
1987	51.3348830377208
1988	51.26780333525353
1989	51.966873368973395
1990	52.17726247328733
1991	51.983246853512945
1992	52.28579213680365
1993	52.56855730845991
1994	52.971599429368936
1995	53.12445164373633
1996	53.2857356888658
1997	53.62736807266499
1998	53.80385407156657
1999	54.79352792778858
2000	55.33614976859317
2001	55.70808004483993
2002	56.06826571337077
2003	56.46318221831801
2004	56.781766925115164
2005	57.13203085983144
2006	57.71495224299507
2007	58.002198787334855
2008	58.18794013237218
2009	58.786513777885986
2010	59.22204705980754
2011	59.71270814093725
2012	59.92848341158407
2013	60.14068109041266
2014	60.467518962982865
2015	60.779636277688184
2016	61.18949398061345
2017	61.51932194256989
2018	61.862584840627505
2019	62.16441459023181
2020	61.67430830116674
2021	61.29119501537765
2022	61.89483006724305