Year	Percent
1970	96.58936
1971	96.79144
1972	97.11286
1973	97.426
1974	97.85082
1975	98.13896
1976	98.41657
1977	98.68421
1978	98.94366
1979	99.30796
1980	99.43375
1981	99.77728
1982	100
1983	100.21505
1984	100.52854
1985	100.72765
1986	100.92025
1987	101.10664
1988	101.38614
1989	101.46056
1990	101.62991
1991	101.88857
1992	102.04651
1993	102.19982
1994	102.34869
1995	102.58467
1996	102.63852
1997	102.86707
1998	103.00429
1999	103.22307
2000	103.35289
2001	103.56551
2002	103.60656
2003	103.81184
2004	103.93258
2005	104.13026
2006	104.24528
2007	104.35798
2008	104.39137
2009	104.50038
2010	104.61073
2011	104.7191
2012	104.74777
2013	104.85294
2014	104.95627
2015	104.98555