Year	years
1960	39.918
1961	40.097
1962	40.399
1963	40.665
1964	40.99
1965	41.384
1966	41.656
1967	42.019
1968	42.454
1969	42.8
1970	43.182
1971	43.5
1972	43.809
1973	44.22
1974	44.596
1975	44.353
1976	44.412
1977	44.68
1978	45.035
1979	45.361
1980	45.608
1981	45.864
1982	46.133
1983	45.435
1984	45.698
1985	45.912
1986	46.037
1987	44.724
1988	45.155
1989	45.33
1990	45.453
1991	46.807
1992	45.484
1993	46.578
1994	47.499
1995	47.829
1996	47.96
1997	48.279
1998	47.618
1999	48.478
2000	48.561
2001	49.606
2002	49.896
2003	51.674
2004	52.657
2005	53.634
2006	54.518
2007	55.815
2008	56.734
2009	57.967
2010	59.039
2011	59.869
2012	61.024
2013	61.684
2014	62.472
2015	63.094
2016	63.434
2017	64.019
2018	64.717
2019	64.922
2020	64.982
2021	64.307
2022	64.541