Year	years
1960	35.199
1961	35.326
1962	35.654
1963	35.618
1964	35.692
1965	35.724
1966	35.866
1967	35.897
1968	36.036
1969	36.321
1970	36.731
1971	37.239
1972	37.904
1973	38.544
1974	39.271
1975	40.222
1976	41.227
1977	42.233
1978	43.29
1979	44.268
1980	45.094
1981	45.701
1982	45.991
1983	46.038
1984	45.579
1985	44.947
1986	44.343
1987	43.811
1988	43.383
1989	43.34
1990	43.323
1991	43.312
1992	43.413
1993	43.388
1994	43.561
1995	43.641
1996	43.441
1997	43.131
1998	42.848
1999	43.568
2000	44.518
2001	45.895
2002	47.221
2003	48.79
2004	50.453
2005	52.044
2006	53.238
2007	53.946
2008	54.604
2009	55.448
2010	56.381
2011	57.455
2012	58.679
2013	59.729
2014	60.899
2015	61.378
2016	62.209
2017	62.977
2018	63.276
2019	64.119
2020	63.717
2021	62.904
2022	62.898