Year	years
1960	74.507
1961	73.006
1962	74.796
1963	73.536
1964	75.413
1965	75.149
1966	75.366
1967	76.176
1968	74.386
1969	74.707
1970	74.55
1971	74.923
1972	75.155
1973	75.379
1974	75.429
1975	74.945
1976	75.662
1977	75.91
1978	76.299
1979	75.73
1980	76.468
1981	76.825
1982	77.593
1983	76.955
1984	78.684
1985	77.927
1986	78.303
1987	79.191
1988	79.525
1989	79.661
1990	79.723
1991	78.824
1992	80.867
1993	79.218
1994	80.28
1995	80.105
1996	80.289
1997	80.483
1998	81.167
1999	81.192
2000	81.393
2001	81.499
2002	81.135
2003	81.775
2004	82.277
2005	82.472
2006	82.846
2007	83.268
2008	83.413
2009	83.175
2010	83.246
2011	83.891
2012	83.432
2013	83.659
2014	84.057
2015	83.552
2016	83.474
2017	83.481
2018	83.525
2019	83.499
2020	83.387
2021	83.355
2022	83.635