Year	years
1960	50.65
1961	51.183
1962	51.716
1963	52.308
1964	52.976
1965	53.614
1966	54.236
1967	54.88
1968	55.511
1969	56.07
1970	56.669
1971	57.246
1972	57.717
1973	58.439
1974	59.032
1975	59.611
1976	60.22
1977	60.78
1978	61.46
1979	62.453
1980	63.332
1981	64.339
1982	65.357
1983	66.273
1984	67.209
1985	67.334
1986	68.301
1987	67.568
1988	69.268
1989	69.363
1990	70.097
1991	70.247
1992	70.44
1993	70.524
1994	70.749
1995	70.845
1996	71.319
1997	71.401
1998	71.473
1999	70.756
2000	71.655
2001	71.674
2002	71.76
2003	71.856
2004	71.872
2005	71.922
2006	71.966
2007	72.041
2008	72.084
2009	72.114
2010	72.056
2011	72.04
2012	71.98
2013	72.055
2014	71.892
2015	71.94
2016	72.126
2017	72.254
2018	72.3
2019	72.405
2020	72.427
2021	72.945
2022	73.067