Year	years
1960	40.857
1961	40.239
1962	40.342
1963	40.604
1964	40.052
1965	40.704
1966	42.053
1967	42.31
1968	42.705
1969	42.976
1970	43.284
1971	43.656
1972	43.933
1973	44.096
1974	44.41
1975	44.471
1976	44.656
1977	44.763
1978	44.537
1979	45.207
1980	45.473
1981	45.72
1982	45.92
1983	46.181
1984	46.445
1985	46.624
1986	46.914
1987	47.336
1988	47.768
1989	48.17
1990	48.601
1991	48.948
1992	49.244
1993	49.551
1994	49.884
1995	50.411
1996	49.307
1997	50.402
1998	49.696
1999	49.945
2000	51.781
2001	52.116
2002	52.333
2003	52.827
2004	53.426
2005	53.927
2006	54.534
2007	54.923
2008	55.339
2009	55.836
2010	56.417
2011	57.069
2012	57.248
2013	57.762
2014	58.296
2015	58.49
2016	59.066
2017	59.411
2018	59.942
2019	60.276
2020	59.739
2021	59.193
2022	59.743