Year	Percent
1970	98.76923
1971	99.39759
1972	100
1973	100.28736
1974	100.8427
1975	101.37363
1976	101.60858
1977	102.09974
1978	102.5641
1979	102.75689
1980	103.18627
1981	103.59712
1982	104.22535
1983	104.5977
1984	104.94382
1985	105.05495
1986	105.37634
1987	105.90717
1988	106.18557
1989	106.46465
1990	106.93069
1991	106.97674
1992	107.41445
1993	107.63501
1994	107.84672
1995	108.05009
1996	108.42105
1997	108.60585
1998	108.9527
1999	109.12106
2000	109.26829
2001	109.56938
2002	109.87461
2003	110.15385
2004	110.42296
2005	110.51852
2006	110.77147
2007	110.85714
2008	111.23596
2009	111.31034
2010	111.51762
2011	111.71771
2012	111.91099
2013	112.09781
2014	112.40506
2015	112.43781