Year	Percent
1970	88.93557
1971	89.28571
1972	89.75741
1973	90.33113
1974	90.76723
1975	91.18774
1976	91.59348
1977	92.10851
1978	92.49395
1979	92.97619
1980	93.44262
1981	93.78596
1982	94.33749
1983	94.65479
1984	95.07119
1985	95.57713
1986	95.96603
1987	96.34274
1988	96.80742
1989	97.16024
1990	97.6024
1991	97.93307
1992	98.34951
1993	98.75598
1994	99.15014
1995	99.53445
1996	99.908
1997	100.18165
1998	100.5386
1999	100.79787
2000	101.13935
2001	101.2987
2002	101.62671
2003	101.86283
2004	102.09205
2005	102.31788
2006	102.5389
2007	102.75527
2008	102.88693
2009	103.09524
2010	103.22074
2011	103.3437
2012	103.54391
2013	103.66133
2014	103.85488
2015	103.89222