Year	Percent
1970	89.73717
1971	90.1599
1972	90.56832
1973	91.08205
1974	91.46199
1975	91.93548
1976	92.40363
1977	92.74554
1978	93.18681
1979	93.61472
1980	93.92324
1981	94.32773
1982	94.7205
1983	95.09704
1984	95.46828
1985	95.8292
1986	96.17647
1987	96.51838
1988	96.84814
1989	97.16981
1990	97.48369
1991	97.88018
1992	98.17851
1993	98.46847
1994	98.84135
1995	99.11817
1996	99.38865
1997	99.65398
1998	100.08576
1999	100.33985
2000	100.58923
2001	100.83403
2002	101.07438
2003	101.39344
2004	101.6247
2005	101.77134
2006	101.99521
2007	102.29612
2008	102.43328
2009	102.56809
2010	102.77778
2011	102.90742
2012	103.11314
2013	103.31325
2014	103.4354
2015	103.55556