Year	years
1960	41.363
1961	41.595
1962	41.874
1963	42.142
1964	42.419
1965	42.75
1966	43.167
1967	43.638
1968	44.111
1969	44.576
1970	44.95
1971	45.393
1972	45.903
1973	46.432
1974	46.965
1975	47.663
1976	48.141
1977	48.629
1978	49.034
1979	49.599
1980	50.001
1981	50.374
1982	50.739
1983	51.13
1984	51.447
1985	51.661
1986	51.944
1987	52.181
1988	52.502
1989	52.555
1990	52.746
1991	52.707
1992	52.947
1993	52.912
1994	52.745
1995	52.735
1996	52.87
1997	52.932
1998	53.058
1999	53.547
2000	53.671
2001	53.988
2002	54.471
2003	54.864
2004	54.999
2005	55.421
2006	55.856
2007	56.111
2008	56.526
2009	56.699
2010	57.225
2011	57.844
2012	58.028
2013	58.544
2014	58.708
2015	59.173
2016	59.325
2017	59.814
2018	59.829
2019	60.35
2020	60.486
2021	60.849
2022	60.946