Year	years
1960	38.211
1961	37.267
1962	37.539
1963	37.824
1964	38.131
1965	38.495
1966	38.757
1967	39.092
1968	39.484
1969	39.829
1970	40.19
1971	40.554
1972	40.905
1973	41.27
1974	41.652
1975	41.191
1976	41.163
1977	41.437
1978	41.83
1979	42.175
1980	42.449
1981	42.772
1982	43.051
1983	42.092
1984	42.353
1985	42.648
1986	42.843
1987	40.917
1988	41.545
1989	41.765
1990	41.893
1991	43.813
1992	42.209
1993	42.101
1994	43.422
1995	45.849
1996	46.033
1997	46.306
1998	45.057
1999	45.386
2000	46.024
2001	46.59
2002	47.386
2003	49.617
2004	50.592
2005	51.57
2006	52.369
2007	53.642
2008	54.633
2009	55.752
2010	56.726
2011	57.596
2012	58.623
2013	59.307
2014	60.04
2015	60.655
2016	61.092
2017	61.68
2018	62.144
2019	62.448
2020	62.261
2021	61.643
2022	61.929