Year	years
1960	35.872
1961	36.24
1962	36.665
1963	36.974
1964	37.251
1965	37.691
1966	37.916
1967	38.294
1968	38.531
1969	38.857
1970	39.239
1971	39.559
1972	40.053
1973	40.548
1974	41.354
1975	42.307
1976	43.245
1977	44.147
1978	45.073
1979	45.903
1980	46.539
1981	46.872
1982	47.602
1983	48.091
1984	48.638
1985	48.949
1986	49.013
1987	49.058
1988	49.132
1989	49.174
1990	49.44
1991	49.45
1992	49.437
1993	49.209
1994	49.307
1995	49.446
1996	49.614
1997	49.4
1998	49.991
1999	50.325
2000	50.847
2001	51.071
2002	51.272
2003	51.793
2004	52.416
2005	53.092
2006	53.742
2007	54.375
2008	55.342
2009	55.959
2010	56.477
2011	57.125
2012	57.619
2013	57.823
2014	58.359
2015	58.845
2016	59.326
2017	59.536
2018	60.047
2019	60.039
2020	59.731
2021	59.27
2022	59.766