Year	years
1960	39.973
1961	40.022
1962	39.899
1963	40.047
1964	40.078
1965	39.948
1966	40.162
1967	40.252
1968	40.416
1969	40.587
1970	41.081
1971	41.534
1972	42.088
1973	42.924
1974	43.682
1975	44.67
1976	45.798
1977	47.008
1978	48.221
1979	49.347
1980	50.438
1981	51.256
1982	52.009
1983	52.726
1984	53.749
1985	54.576
1986	55.873
1987	56.793
1988	57.937
1989	58.696
1990	59.256
1991	59.321
1992	59.221
1993	59.013
1994	58.772
1995	58.554
1996	58.266
1997	58.21
1998	57.922
1999	57.846
2000	58.097
2001	58.73
2002	59.251
2003	60.338
2004	61.136
2005	62.072
2006	62.979
2007	63.87
2008	64.647
2009	65.524
2010	66.334
2011	67.174
2012	67.456
2013	68.236
2014	68.411
2015	69.085
2016	69.787
2017	70.066
2018	70.258
2019	70.954
2020	70.271
2021	69.284
2022	70.2