Year	years
1960	34.837
1961	35.145
1962	35.598
1963	35.941
1964	36.124
1965	36.531
1966	36.757
1967	37.111
1968	37.293
1969	37.577
1970	37.925
1971	38.194
1972	38.763
1973	39.205
1974	40.009
1975	40.962
1976	41.92
1977	42.787
1978	43.723
1979	44.506
1980	45.236
1981	45.626
1982	46.376
1983	46.892
1984	47.493
1985	47.814
1986	47.981
1987	48.03
1988	48.178
1989	48.225
1990	48.383
1991	48.396
1992	48.382
1993	48.12
1994	48.071
1995	48.224
1996	48.313
1997	48.176
1998	48.691
1999	48.875
2000	49.225
2001	49.471
2002	49.752
2003	50.32
2004	50.953
2005	51.479
2006	52.234
2007	52.878
2008	53.745
2009	54.493
2010	54.959
2011	55.527
2012	56.033
2013	56.277
2014	56.727
2015	57.184
2016	57.623
2017	57.797
2018	58.29
2019	58.173
2020	57.787
2021	57.474
2022	57.953