Year	years
1960	37.889
1961	38.047
1962	38.223
1963	38.542
1964	38.69
1965	38.969
1966	39.135
1967	39.455
1968	39.959
1969	40.113
1970	40.4
1971	40.686
1972	41.075
1973	41.184
1974	41.432
1975	41.92
1976	42.316
1977	42.79
1978	43.31
1979	43.82
1980	44.322
1981	44.745
1982	45.211
1983	45.667
1984	46.093
1985	46.666
1986	46.916
1987	47.36
1988	47.364
1989	47.498
1990	47.522
1991	48.198
1992	49.161
1993	49.761
1994	49.945
1995	50.568
1996	51.173
1997	52.033
1998	52.489
1999	52.763
2000	52.832
2001	53.118
2002	53.643
2003	54.085
2004	54.649
2005	55.288
2006	55.851
2007	56.447
2008	57.042
2009	57.309
2010	57.842
2011	58.107
2012	58.731
2013	59.007
2014	59.248
2015	59.307
2016	59.69
2017	60.212
2018	60.298
2019	60.817
2020	60.449
2021	60.099
2022	60.238