Year	Percent
1970	86.10526
1971	86.80412
1972	87.09677
1973	87.54941
1974	88.00774
1975	88.44697
1976	88.86827
1977	89.45455
1978	89.83957
1979	90.38462
1980	90.75342
1981	91.2605
1982	91.76277
1983	92.08401
1984	92.55151
1985	93.00156
1986	93.43511
1987	93.85307
1988	94.26471
1989	94.79769
1990	95.03546
1991	95.4039
1992	96.0274
1993	96.36608
1994	96.69312
1995	97.13914
1996	97.57033
1997	97.73869
1998	98.14586
1999	98.54015
2000	98.92344
2001	99.29329
2002	99.5365
2003	99.88597
2004	100.33708
2005	100.5531
2006	100.87146
2007	101.18026
2008	101.37421
2009	101.66667
2010	101.95072
2011	102.22672
2012	102.49501
2013	102.65748
2014	103.01263
2015	103.25983