Year	years
1960	32.535
1961	33.068
1962	33.547
1963	34.016
1964	34.494
1965	34.953
1966	35.453
1967	35.924
1968	36.418
1969	36.91
1970	37.418
1971	37.923
1972	38.444
1973	39.003
1974	39.55
1975	40.1
1976	40.645
1977	41.228
1978	40.271
1979	39.086
1980	39.618
1981	40.164
1982	37.766
1983	38.187
1984	33.329
1985	33.55
1986	39.396
1987	39.844
1988	43.958
1989	45.158
1990	45.967
1991	46.663
1992	47.596
1993	51.466
1994	51.495
1995	52.544
1996	53.243
1997	53.634
1998	52.943
1999	54.846
2000	55.298
2001	55.798
2002	56.454
2003	57.344
2004	57.944
2005	58.361
2006	58.684
2007	59.111
2008	59.852
2009	60.364
2010	60.851
2011	61.419
2012	61.923
2013	62.417
2014	62.545
2015	62.659
2016	63.136
2017	63.016
2018	63.081
2019	63.565
2020	62.575
2021	61.982
2022	62.879