Year	Percent
1970	87.84153
1971	88.32215
1972	88.78628
1973	89.11917
1974	89.55414
1975	90.10025
1976	90.39409
1977	90.90909
1978	91.17998
1979	91.66667
1980	92.02312
1981	92.3777
1982	92.82511
1983	93.14917
1984	93.57298
1985	93.87755
1986	94.27359
1987	94.56067
1988	94.93802
1989	95.30612
1990	95.66532
1991	95.91633
1992	96.25984
1993	96.59202
1994	96.91715
1995	97.14013
1996	97.54485
1997	97.75701
1998	98.05556
1999	98.25848
2000	98.6376
2001	98.83094
2002	99.10873
2003	99.38217
2004	99.65035
2005	99.91342
2006	100.08576
2007	100.42481
2008	100.58873
2009	100.83333
2010	100.9901
2011	101.22549
2012	101.3754
2013	101.60256
2014	101.8254
2015	101.96541