Year	years
1960	68.295
1961	66.455
1962	69.154
1963	67.043
1964	69.422
1965	68.831
1966	69.262
1967	70.156
1968	67.982
1969	68.26
1970	67.765
1971	68.402
1972	68.537
1973	68.855
1974	68.974
1975	68.313
1976	69.384
1977	69.658
1978	70.015
1979	69.223
1980	70.276
1981	70.759
1982	71.961
1983	71.006
1984	73.248
1985	72.435
1986	72.763
1987	73.838
1988	74.33
1989	74.524
1990	74.436
1991	74.219
1992	75.188
1993	73.759
1994	75.52
1995	75.214
1996	75.46
1997	75.766
1998	76.443
1999	76.505
2000	76.755
2001	76.907
2002	76.561
2003	77.323
2004	77.826
2005	78.073
2006	78.403
2007	78.914
2008	79.081
2009	78.721
2010	78.904
2011	79.466
2012	79.172
2013	79.31
2014	79.649
2015	79.268
2016	79.22
2017	79.158
2018	79.205
2019	79.266
2020	79.141
2021	79.115
2022	79.521