Year	years
1960	37.004
1961	37.436
1962	37.823
1963	38.086
1964	38.465
1965	38.937
1966	39.154
1967	39.551
1968	39.842
1969	40.207
1970	40.62
1971	40.988
1972	41.389
1973	41.934
1974	42.733
1975	43.676
1976	44.584
1977	45.516
1978	46.426
1979	47.299
1980	47.83
1981	48.097
1982	48.799
1983	49.255
1984	49.741
1985	50.038
1986	49.995
1987	50.033
1988	50.031
1989	50.065
1990	50.436
1991	50.439
1992	50.42
1993	50.22
1994	50.461
1995	50.578
1996	50.823
1997	50.526
1998	51.191
1999	51.679
2000	52.376
2001	52.578
2002	52.7
2003	53.172
2004	53.786
2005	54.617
2006	55.158
2007	55.777
2008	56.842
2009	57.32
2010	57.888
2011	58.616
2012	59.096
2013	59.262
2014	59.884
2015	60.401
2016	60.927
2017	61.178
2018	61.706
2019	61.822
2020	61.598
2021	60.99
2022	61.505