Year	years
1960	31.349
1961	31.69
1962	30.876
1963	30.351
1964	32.101
1965	32.767
1966	33.416
1967	34.127
1968	35.128
1969	36.969
1970	38.012
1971	39.262
1972	40.124
1973	41.069
1974	42.077
1975	43.013
1976	43.916
1977	45.105
1978	46.255
1979	47.197
1980	48.48
1981	49.562
1982	50.389
1983	51.748
1984	52.788
1985	53.674
1986	49.847
1987	55.12
1988	55.752
1989	56.283
1990	56.811
1991	57.04
1992	57.523
1993	58.001
1994	57.571
1995	58.593
1996	58.693
1997	59.23
1998	59.46
1999	60.024
2000	60.619
2001	61.27
2002	61.946
2003	62.556
2004	63.138
2005	63.65
2006	63.939
2007	64.535
2008	65.037
2009	65.076
2010	65.165
2011	65.348
2012	65.275
2013	65.557
2014	65.334
2015	63.005
2016	63.32
2017	63.108
2018	60.901
2019	61.807
2020	61.636
2021	60.629
2022	60.493