Year	Percent
1970	92.10867
1971	92.61146
1972	92.98246
1973	93.34155
1974	93.92467
1975	94.25837
1976	94.58186
1977	95.12195
1978	95.42334
1979	95.93679
1980	96.21802
1981	96.70692
1982	97.07792
1983	97.4359
1984	97.8903
1985	98.22917
1986	98.66255
1987	99.08537
1988	99.39759
1989	99.80159
1990	100.09804
1991	100.48497
1992	100.95969
1993	101.32953
1994	101.69173
1995	101.95349
1996	102.29991
1997	102.63876
1998	103.06031
1999	103.29181
2000	103.60915
2001	103.74238
2002	103.95869
2003	104.25894
2004	104.46504
2005	104.67056
2006	104.86799
2007	104.97959
2008	105.25465
2009	105.36
2010	105.54675
2011	105.56863
2012	105.74981
2013	105.84615
2014	105.94512
2015	106.0423