Year	% of total
1960	100
1961	100
1962	100
1963	100
1964	100
1965	100
1966	100
1967	100
1968	100
1969	100
1970	100
1971	100
1972	100
1973	97.75280898876404
1974	92.07920792079207
1975	95.15151515151517
1976	95.97989949748745
1977	96.61016949152543
1978	96.52509652509652
1979	95.78947368421052
1980	96.62576687116564
1981	97.03504043126682
1982	94.00749063670412
1983	82.9160530191458
1984	76.49253731343283
1985	77.93263646922183
1986	81.62790697674419
1987	88.74316939890711
1988	90.52744886975242
1989	90.041928721174
1990	50.47647590361446
1991	103.32311764705881
1992	104.62798466593648
1993	102.28762315270934
1994	102.18303066037736
1995	100.53598784194529
1996	100.44233134920634
1997	99.87082949308757
1998	98.91208866155159
1999	99.98630979498861
2000	100.4002951763859
2001	102.54468832891246
2002	98.98962351387054
2003	95.02587931034483
2004	98.43104891304347
2005	99.4328431372549
2006	106.04261205564143
2007	97.47856519631604
2008	96.13171285779191
2009	87.85074074074075
2010	83.79530637765735
2011	84.34631706138231
2012	77.8864837398374
2013	80.9801631878558
2014	77.76071883189816
2015	65.95954961294863
2016	74.4859375