Year	Percent
1970	96.65653
1971	97.16418
1972	97.50733
1973	97.83862
1974	98.30028
1975	98.74652
1976	99.0411
1977	99.46092
1978	99.86737
1979	100.2611
1980	100.51348
1981	100.88496
1982	101.24533
1983	101.59509
1984	101.9347
1985	102.2646
1986	102.58519
1987	102.781
1988	103.08571
1989	103.49887
1990	103.67483
1991	103.9604
1992	104.34783
1993	104.61869
1994	104.77707
1995	105.03673
1996	105.29046
1997	105.53279
1998	105.66802
1999	105.9
2000	106.12648
2001	106.34766
2002	106.56371
2003	106.67302
2004	106.8803
2005	106.98324
2006	107.2744
2007	107.37034
2008	107.46403
2009	107.55556
2010	107.73967
2011	107.82609
2012	107.91058
2013	107.9932
2014	108.07401
2015	108.24313