Year	years
1960	56.016
1961	52.522
1962	56.989
1963	57.607
1964	58.26
1965	58.99
1966	59.228
1967	59.631
1968	60.515
1969	61.087
1970	61.72
1971	62.905
1972	63.152
1973	62.843
1974	63.492
1975	64.58
1976	64.52
1977	64.594
1978	65.096
1979	65.701
1980	66.267
1981	66.699
1982	66.797
1983	66.738
1984	66.839
1985	68.278
1986	67.988
1987	68.458
1988	69.131
1989	68.803
1990	69.139
1991	68.721
1992	68.614
1993	68.474
1994	68.351
1995	67.978
1996	67.671
1997	67.187
1998	66.536
1999	66.591
2000	66.338
2001	66.057
2002	66.306
2003	66.518
2004	66.893
2005	67.177
2006	67.717
2007	68.168
2008	68.618
2009	69.175
2010	69.588
2011	70.019
2012	70.714
2013	71.35
2014	70.674
2015	70.357
2016	70.584
2017	70.731
2018	70.84
2019	71.062
2020	69.564
2021	67.119
2022	67.721