Year	Percent
1970	96.77104
1971	97.11261
1972	97.25639
1973	97.48603
1974	97.70852
1975	97.92231
1976	98.13167
1977	98.24561
1978	98.44291
1979	98.54825
1980	98.73524
1981	98.91667
1982	98.93004
1983	99.10423
1984	99.1942
1985	99.2823
1986	99.28966
1987	99.37451
1988	99.45736
1989	99.53882
1990	99.6189
1991	99.62207
1992	99.62491
1993	99.77645
1994	99.85196
1995	99.85294
1996	100
1997	100.07262
1998	100.1444
1999	100.28715
2000	100.35663
2001	100.49645
2002	100.56378
2003	100.77085
2004	100.83565
2005	100.89965
2006	101.10117
2007	101.16279
2008	101.29164
2009	101.35135
2010	101.4775
2011	101.60214
2012	101.72528
2013	101.781
2014	101.83486
2015	101.9544