Year	years
1960	41.533
1961	41.804
1962	42.102
1963	42.358
1964	42.543
1965	40.087
1966	42.155
1967	41.912
1968	41.98
1969	41.379
1970	41.69
1971	41.625
1972	23.209
1973	35.36
1974	41.741
1975	41.796
1976	41.837
1977	42.114
1978	42.368
1979	43.144
1980	43.897
1981	44.923
1982	45.88
1983	46.667
1984	47.009
1985	46.971
1986	46.503
1987	45.73
1988	40.601
1989	43.785
1990	43.011
1991	42.539
1992	42.474
1993	34.984
1994	42.521
1995	42.257
1996	42.435
1997	43.521
1998	44.621
1999	45.699
2000	45.272
2001	46.127
2002	47.902
2003	49.072
2004	50.374
2005	51.387
2006	52.291
2007	53.279
2008	53.963
2009	54.772
2010	55.714
2011	56.396
2012	57.086
2013	57.776
2014	58.35
2015	58.226
2016	59.088
2017	59.764
2018	59.821
2019	60.339
2020	59.465
2021	59.711
2022	60.077