Year	Percent
1970	88.0775
1971	88.5798
1972	89.06475
1973	89.40678
1974	89.87517
1975	90.4502
1976	90.75067
1977	91.1726
1978	91.70984
1979	92.21939
1980	92.59724
1981	92.96296
1982	93.43864
1983	93.7799
1984	94.2285
1985	94.54756
1986	95.08009
1987	95.49042
1988	95.77778
1989	96.27193
1990	96.54054
1991	97.01174
1992	97.26316
1993	97.7131
1994	98.04928
1995	98.37728
1996	98.79639
1997	99.00892
1998	99.41176
1999	99.7093
2000	100
2001	100.28409
2002	100.65543
2003	100.83256
2004	101.0979
2005	101.44796
2006	101.61002
2007	101.76835
2008	102.09974
2009	102.24913
2010	102.48075
2011	102.62267
2012	102.76151
2013	103.06545
2014	103.19672
2015	103.32522