Year	Percent
1970	93.21825
1971	93.57576
1972	93.92133
1973	94.3662
1974	94.68822
1975	95.11364
1976	95.52072
1977	95.92062
1978	96.19978
1979	96.68094
1980	97.04641
1981	97.39854
1982	97.84394
1983	98.17629
1984	98.6
1985	98.91412
1986	99.31774
1987	99.71098
1988	100
1989	100.37629
1990	100.74419
1991	101.19705
1992	101.54827
1993	101.98377
1994	102.32143
1995	102.74336
1996	103.15789
1997	103.47524
1998	103.78984
1999	104.18446
2000	104.48393
2001	104.78188
2002	105.07066
2003	105.27183
2004	105.63725
2005	105.82996
2006	106.01926
2007	106.20525
2008	106.30418
2009	106.48438
2010	106.6615
2011	106.75883
2012	106.84932
2013	106.9434
2014	107.03593
2015	107.12166