Year	Percent
1970	88.63158
1971	89.11704
1972	89.95984
1973	90.39216
1974	90.99617
1975	91.7603
1976	92.13894
1977	92.67857
1978	93.36824
1979	94.0273
1980	94.5
1981	95.11401
1982	95.54849
1983	96.11198
1984	96.65653
1985	97.03264
1986	97.53623
1987	98.017
1988	98.47645
1989	98.91746
1990	99.2074
1991	99.6129
1992	100.1261
1993	100.49261
1994	100.84135
1995	101.0551
1996	101.37615
1997	101.56951
1998	101.75631
1999	102.04301
2000	102.21286
2001	102.37603
2002	102.5355
2003	102.68924
2004	102.83757
2005	102.98077
2006	103.12204
2007	103.25885
2008	103.39138
2009	103.61337
2010	103.64769
2011	103.77193
2012	103.8961
2013	103.92827
2014	104.04722
2015	104.1632