Year	years
1960	40.084
1961	40.093
1962	40.18
1963	40.22
1964	40.334
1965	40.554
1966	40.849
1967	41.101
1968	41.483
1969	41.91
1970	42.309
1971	42.665
1972	43.184
1973	43.607
1974	44.038
1975	44.344
1976	44.789
1977	45.201
1978	45.607
1979	45.85
1980	46.21
1981	46.473
1982	46.653
1983	46.81
1984	46.898
1985	46.361
1986	46.44
1987	45.975
1988	45.515
1989	45.092
1990	44.219
1991	44.802
1992	45.361
1993	44.752
1994	44.736
1995	46.399
1996	47.052
1997	49.768
1998	50.818
1999	52.125
2000	53.214
2001	54.534
2002	55.495
2003	55.527
2004	57.686
2005	58.544
2006	59.063
2007	59.692
2008	60.137
2009	60.551
2010	60.644
2011	60.842
2012	61.148
2013	61.124
2014	60.213
2015	60.373
2016	61.554
2017	61.694
2018	62.164
2019	62.298
2020	62.355
2021	62.072
2022	62.392