Year	years
1960	44.182
1961	44.363
1962	44.515
1963	44.795
1964	45.023
1965	45.422
1966	45.85
1967	46.375
1968	47.132
1969	47.874
1970	48.459
1971	48.915
1972	49.21
1973	50.04
1974	50.404
1975	50.78
1976	51.284
1977	51.924
1978	52.43
1979	53.073
1980	53.472
1981	53.863
1982	53.876
1983	53.932
1984	54.024
1985	53.971
1986	54.033
1987	54.055
1988	54.051
1989	53.995
1990	53.514
1991	53.427
1992	53.106
1993	52.827
1994	52.816
1995	52.576
1996	52.376
1997	51.936
1998	52.053
1999	53.021
2000	53.516
2001	54.371
2002	55.086
2003	56.061
2004	56.744
2005	57.432
2006	58.184
2007	58.882
2008	59.44
2009	60.223
2010	61.914
2011	63.082
2012	64.218
2013	65.317
2014	66.274
2015	67.029
2016	67.691
2017	68.207
2018	68.649
2019	69.117
2020	68.542
2021	68.311
2022	68.93