Year	Percent
1970	89.63731
1971	90.12658
1972	90.59406
1973	91.28329
1974	91.70616
1975	92.12963
1976	92.53394
1977	93.12639
1978	93.49241
1979	93.85593
1980	94.39834
1981	94.9187
1982	95.22863
1983	95.71984
1984	96
1985	96.45522
1986	96.89214
1987	97.49104
1988	97.7193
1989	98.27883
1990	98.65093
1991	99.00826
1992	99.3517
1993	99.84102
1994	100.15601
1995	100.45872
1996	100.9009
1997	101.1782
1998	101.5919
1999	101.98864
2000	102.23152
2001	102.60274
2002	103.09973
2003	103.30688
2004	103.64109
2005	103.96419
2006	104.27673
2007	104.57355
2008	104.86618
2009	105.14354
2010	105.41814
2011	105.67787
2012	105.9293
2013	106.06061
2014	106.29834
2015	106.64488