Year	Percent
1970	91.35802
1971	91.68111
1972	92.0068
1973	92.47492
1974	92.77504
1975	93.21486
1976	93.49206
1977	93.90625
1978	94.16283
1979	94.56193
1980	94.94048
1981	95.16837
1982	95.5267
1983	95.88068
1984	96.08392
1985	96.55172
1986	96.73913
1987	97.05489
1988	97.22955
1989	97.65625
1990	97.81772
1991	98.10127
1992	98.25218
1993	98.52217
1994	98.78493
1995	99.04077
1996	99.40898
1997	99.76717
1998	100
1999	100.22573
2000	100.55617
2001	100.87719
2002	101.18919
2003	101.38445
2004	101.78571
2005	101.96687
2006	102.24719
2007	102.41692
2008	102.7833
2009	102.94118
2010	103.19458
2011	103.4384
2012	103.67925
2013	103.8175
2014	104.13983
2015	104.26885