Year	Percent
1970	93.51955
1971	93.94939
1972	94.25785
1973	94.66382
1974	95.05783
1975	95.34161
1976	95.71429
1977	96.17706
1978	96.52778
1979	96.77419
1980	97.10704
1981	97.43102
1982	97.74859
1983	98.05556
1984	98.35466
1985	98.64621
1986	98.93048
1987	99.12049
1988	99.39183
1989	99.65665
1990	99.91518
1991	100.16764
1992	100.41425
1993	100.65574
1994	100.89141
1995	101.04167
1996	101.26883
1997	101.41176
1998	101.5528
1999	101.76787
2000	101.90259
2001	102.03466
2002	102.16418
2003	102.36686
2004	102.41758
2005	102.54176
2006	102.66379
2007	102.78373
2008	102.90368
2009	103.01966
2010	103.06407
2011	103.17899
2012	103.22359
2013	103.3356
2014	103.37838
2015	103.48993