Year	years
1960	47.501
1961	47.917
1962	48.331
1963	48.409
1964	51.319
1965	49.104
1966	47.063
1967	47.485
1968	47.891
1969	47.797
1970	48.177
1971	52.153
1972	52.163
1973	54.592
1974	54.77
1975	54.885
1976	55.031
1977	55.176
1978	54.721
1979	54.878
1980	55.606
1981	55.835
1982	56.006
1983	49.927
1984	49.235
1985	49.516
1986	54.919
1987	49.261
1988	43.163
1989	53.726
1990	54.143
1991	54.563
1992	51.397
1993	51.98
1994	59.14
1995	56.151
1996	56.489
1997	57.07
1998	54.266
1999	60.106
2000	61.271
2001	61.629
2002	61.985
2003	61.517
2004	60.569
2005	61.022
2006	63.021
2007	64.052
2008	63.96
2009	65.321
2010	65.506
2011	65.801
2012	66.447
2013	66.597
2014	67.233
2015	67.349
2016	67.432
2017	68.018
2018	68.233
2019	68.388
2020	68.208
2021	67.879
2022	68.184