Year	years
1960	41.729
1961	41.994
1962	42.258
1963	42.546
1964	42.749
1965	43.054
1966	43.264
1967	43.532
1968	43.731
1969	30.076
1970	30.248
1971	36.263
1972	43.284
1973	43.477
1974	40.186
1975	35.812
1976	28.921
1977	40.501
1978	40.793
1979	41.653
1980	47.563
1981	48.109
1982	48.596
1983	49.007
1984	49.208
1985	49.683
1986	50.039
1987	50.279
1988	50.504
1989	50.668
1990	50.86
1991	50.969
1992	51.113
1993	51.308
1994	51.415
1995	51.592
1996	51.727
1997	52.061
1998	52.382
1999	52.752
2000	53.226
2001	53.636
2002	54.085
2003	54.581
2004	55.036
2005	55.464
2006	56.046
2007	56.54
2008	57.074
2009	57.431
2010	57.878
2011	58.412
2012	58.865
2013	59.224
2014	59.595
2015	60.103
2016	60.479
2017	60.821
2018	61.191
2019	61.644
2020	60.708
2021	60.594
2022	61.19