Year	Percent
1970	92.65464
1971	93.03797
1972	93.52428
1973	93.88005
1974	94.34416
1975	94.78673
1976	95.1049
1977	95.41284
1978	95.82393
1979	96.21802
1980	96.6046
1981	96.87163
1982	97.23404
1983	97.48428
1984	97.93175
1985	98.16514
1986	98.49095
1987	98.70904
1988	99.11678
1989	99.4186
1990	99.61722
1991	99.90539
1992	100.18709
1993	100.37003
1994	100.7326
1995	100.9058
1996	101.16697
1997	101.42349
1998	101.5859
1999	101.83406
2000	101.98962
2001	102.31561
2002	102.46389
2003	102.69587
2004	102.83806
2005	103.06291
2006	103.28138
2007	103.41463
2008	103.54553
2009	103.75399
2010	103.87965
2011	104.00314
2012	104.12131
2013	104.24056
2014	104.43425
2015	104.4697