Year	Percent
1970	75.43491
1971	74.82918
1972	84.32016
1973	89.24927
1974	88.27315
1975	83.93084
1976	79.92882
1977	86.63843
1978	83.10594
1979	81.44284
1980	82.27822
1981	85.84383
1982	86.39487
1985	77.03876
1986	78.39849
1987	75.58574
1988	75.52724
1989	74.6622
1991	78.46455
1992	80.54541
1993	82.87894
1994	81.19588
1995	80.62524
1996	81.71853
1999	84.77638
2000	90.88123
2001	93.52437
2002	96.57309
2004	96.09712
2005	95.19769
2006	90.70434
2007	92.81426
2008	93.39698
2009	97.78942
2010	98.82868
2011	103.25574
2012	101.61164
2013	98.6297
2014	99.01087
2015	99.17616
2016	95.65431