Year	Percent
1970	95.20548
1971	95.50562
1972	95.68584
1973	96.07415
1974	96.34801
1975	96.50794
1976	96.86848
1977	97.01646
1978	97.25888
1979	97.49499
1980	97.72502
1981	97.94922
1982	98.07136
1983	98.28408
1984	98.39925
1985	98.60335
1986	98.80295
1987	98.99727
1988	99.09829
1989	99.19643
1990	99.38108
1991	99.47461
1992	99.65278
1993	99.74205
1994	99.91475
1995	100.08453
1996	100.1675
1997	100.33223
1998	100.49383
1999	100.65253
2000	100.72757
2001	100.88141
2002	101.11199
2003	101.18017
2004	101.40406
2005	101.46832
2006	101.60796
2007	101.74507
2008	101.8797
2009	102.01192
2010	102.21566
2011	102.34261
2012	102.46734
2013	102.58993
2014	102.63721
2015	102.75618