Year	years
1960	55.866
1961	56.198
1962	56.602
1963	57.01
1964	57.43
1965	57.846
1966	58.287
1967	58.725
1968	59.157
1969	59.621
1970	60.004
1971	60.316
1972	60.549
1973	60.775
1974	61.08
1975	61.334
1976	61.606
1977	61.764
1978	62.058
1979	62.274
1980	62.465
1981	62.645
1982	62.616
1983	62.855
1984	62.973
1985	63.136
1986	63.257
1987	63.39
1988	63.533
1989	63.688
1990	63.835
1991	64.033
1992	64.208
1993	64.39
1994	64.569
1995	64.74
1996	64.92
1997	65.135
1998	65.288
1999	65.486
2000	65.7
2001	65.924
2002	66.176
2003	66.388
2004	66.625
2005	66.836
2006	67.013
2007	67.233
2008	67.382
2009	67.277
2010	67.567
2011	67.63
2012	67.709
2013	67.79
2014	67.844
2015	67.925
2016	67.991
2017	68.065
2018	68.149
2019	68.265
2020	68.337
2021	68.416
2022	68.581