Year	Percent
1970	90.12346
1971	90.62027
1972	91.0847
1973	91.69096
1974	92.13162
1975	92.42637
1976	92.97521
1977	93.37838
1978	94.0239
1979	94.39374
1980	94.87836
1981	95.22613
1982	95.67901
1983	96.1165
1984	96.5435
1985	96.9555
1986	97.46544
1987	97.84824
1988	98.21826
1989	98.68565
1990	98.92357
1991	99.36441
1992	99.79145
1993	100.20534
1994	100.50505
1995	100.89552
1996	101.17647
1997	101.54589
1998	101.90658
1999	102.06767
2000	102.41187
2001	102.74725
2002	102.98373
2003	103.12221
2004	103.43612
2005	103.56832
2006	103.78332
2007	104.08163
2008	104.20168
2009	104.31894
2010	104.51931
2011	104.63038
2012	104.82315
2013	104.93238
2014	105.03541
2015	105.14019