Year	Percent
1970	93.75
1971	94.22604
1972	94.56522
1973	95.12485
1974	95.4386
1975	95.85731
1976	96.26274
1977	96.65552
1978	96.92982
1979	97.30022
1980	97.65957
1981	98.00839
1982	98.34711
1983	98.67617
1984	98.99598
1985	99.40594
1986	99.70703
1987	100
1988	100.19011
1989	100.46904
1990	100.74074
1991	101.0064
1992	101.26468
1993	101.51786
1994	101.67549
1995	101.91805
1996	102.15517
1997	102.38704
1998	102.52951
1999	102.66889
2000	102.88779
2001	103.02041
2002	103.23363
2003	103.28
2004	103.40459
2005	103.60784
2006	103.64907
2007	103.76923
2008	103.8872
2009	104.00302
2010	104.11677
2011	104.1543
2012	104.26471
2013	104.30029
2014	104.33526
2015	104.44444