Year	Percent
1970	90.84065
1971	91.25616
1972	91.53567
1973	91.92399
1974	92.29872
1975	92.66055
1976	92.89741
1977	93.23725
1978	93.45692
1979	93.87755
1980	94.17989
1981	94.375
1982	94.66119
1983	94.93927
1984	95.2048
1985	95.46798
1986	95.71984
1987	95.87332
1988	96.11374
1989	96.43861
1990	96.57407
1991	96.7033
1992	97.00816
1993	97.21724
1994	97.41993
1995	97.53086
1996	97.81469
1997	98.09359
1998	98.28326
1999	98.55319
2000	98.81956
2001	98.99749
2002	99.25497
2003	99.50779
2004	99.6748
2005	99.83897
2006	100.07981
2007	100.31646
2008	100.47022
2009	100.6993
2010	100.92379
2011	101.06789
2012	101.21029
2013	101.34933
2014	101.56134
2015	101.69492