Year	years
1960	57.125
1961	57.251
1962	57.654
1963	57.918
1964	58.271
1965	58.749
1966	58.771
1967	59.095
1968	59.559
1969	59.793
1970	59.985
1971	60.267
1972	60.632
1973	61.107
1974	61.235
1975	61.476
1976	61.767
1977	62.155
1978	62.508
1979	62.785
1980	63.239
1981	63.413
1982	63.741
1983	63.622
1984	63.834
1985	64.046
1986	64.074
1987	64.046
1988	64.148
1989	63.819
1990	63.827
1991	63.583
1992	62.911
1993	62.607
1994	64.176
1995	64.245
1996	64.325
1997	64.583
1998	64.879
1999	65.09
2000	65.348
2001	65.225
2002	65.537
2003	65.853
2004	66.166
2005	66.529
2006	66.731
2007	67.193
2008	66.705
2009	67.391
2010	67.603
2011	67.856
2012	67.651
2013	67.866
2014	68.309
2015	68.477
2016	68.696
2017	68.836
2018	68.495
2019	68.493
2020	67.74
2021	66.803
2022	66.76