Year	Percent
1970	88.70152
1971	89.22056
1972	89.73941
1973	90.08
1974	90.40881
1975	90.88099
1976	91.33739
1977	91.49254
1978	91.92364
1979	92.34104
1980	92.74538
1981	93.13725
1982	93.51724
1983	93.88587
1984	94.36997
1985	94.71598
1986	95.05208
1987	95.50129
1988	95.81749
1989	96.12015
1990	96.53894
1991	96.9475
1992	97.22557
1993	97.61621
1994	97.99528
1995	98.48308
1996	98.84925
1997	99.20545
1998	99.55207
1999	99.8895
2000	100.32715
2001	100.53763
2002	100.84836
2003	101.25654
2004	101.54959
2005	101.83486
2006	102.11268
2007	102.38332
2008	102.64706
2009	102.90135
2010	103.15186
2011	103.39623
2012	103.63467
2013	103.77185
2014	104
2015	104.22282