Year	Percent
1970	64.28676
1983	82.48238
1985	84.29896
1986	83.64157
1987	88.99821
1989	94.93591
1990	96.48167
1991	99.22812
1992	99.13234
1998	97.45629
2001	107.95078
2002	114.04066
2003	105.47837
2005	101.36808
2006	100.12507
2007	97.86356
2008	92.62015
2009	92.86403
2010	100.12928
2011	102.50682
2012	98.23267
2013	99.88067
2014	99.09906
2015	99.7427
2016	101.7266