Year	Percent
1970	92.91498
1971	93.45238
1972	93.78641
1973	94.29658
1974	94.78585
1975	95.25547
1976	95.70662
1977	96.31579
1978	96.7354
1979	97.30185
1980	97.68595
1981	98.05511
1982	98.72611
1983	99.21875
1984	99.53988
1985	100
1986	100.59172
1987	100.87083
1988	101.42653
1989	101.82328
1990	102.34483
1991	102.71003
1992	103.2
1993	103.67454
1994	104
1995	104.44727
1996	104.8811
1997	105.17241
1998	105.58252
1999	105.85424
2000	106.23529
2001	106.48899
2002	106.73516
2003	107.08661
2004	107.19823
2005	107.53275
2006	107.75027
2007	107.95334
2008	108.159
2009	108.35052
2010	108.53659
2011	108.72618
2012	108.80317
2013	109.08203
2014	109.15222
2015	109.31559