Year	years
1960	39.878
1961	39.917
1962	39.856
1963	39.882
1964	39.885
1965	39.838
1966	39.961
1967	40.083
1968	40.268
1969	40.459
1970	40.825
1971	41.219
1972	41.753
1973	42.557
1974	43.211
1975	44.099
1976	45.098
1977	46.152
1978	47.197
1979	48.196
1980	49.142
1981	49.85
1982	50.564
1983	51.153
1984	52.015
1985	52.758
1986	53.928
1987	54.819
1988	55.774
1989	56.438
1990	56.948
1991	57.139
1992	57.112
1993	56.996
1994	56.955
1995	56.839
1996	56.672
1997	56.591
1998	56.418
1999	56.609
2000	56.943
2001	57.564
2002	58.231
2003	59.122
2004	60.027
2005	60.915
2006	61.75
2007	62.543
2008	63.242
2009	63.923
2010	64.615
2011	65.262
2012	65.457
2013	66.072
2014	66.452
2015	66.879
2016	67.497
2017	67.75
2018	68.097
2019	68.526
2020	68.006
2021	67.093
2022	67.913