Year	years
1960	39.236
1961	39.737
1962	40.256
1963	40.781
1964	41.345
1965	41.929
1966	42.531
1967	43.158
1968	43.797
1969	44.442
1970	45.072
1971	45.688
1972	46.294
1973	46.854
1974	47.402
1975	47.913
1976	48.395
1977	48.838
1978	49.239
1979	49.597
1980	49.889
1981	50.159
1982	50.303
1983	50.423
1984	50.484
1985	50.518
1986	50.492
1987	50.409
1988	50.241
1989	49.986
1990	49.635
1991	49.252
1992	48.793
1993	48.353
1994	47.853
1995	47.35
1996	46.831
1997	46.319
1998	46.025
1999	45.75
2000	45.406
2001	45.393
2002	45.409
2003	45.76
2004	46.038
2005	46.433
2006	46.851
2007	47.426
2008	48.016
2009	48.648
2010	49.255
2011	49.948
2012	50.686
2013	50.902
2014	50.566
2015	52.793
2016	53.46
2017	53.721
2018	54.369
2019	55.025
2020	54.604
2021	53.895
2022	54.477