Year	Percent
1970	98.56887
1971	98.77408
1972	99.14237
1973	99.4958
1974	99.83526
1975	100.16129
1976	100.31596
1977	100.6192
1978	100.91047
1979	101.19048
1980	101.45773
1981	101.71429
1982	101.82073
1983	102.06044
1984	102.42588
1985	102.50991
1986	102.85344
1987	102.92621
1988	103.1211
1989	103.30882
1990	103.48558
1991	103.65998
1992	103.82387
1993	103.86803
1994	104.02235
1995	104.28101
1996	104.42765
1997	104.67588
1998	104.92147
1999	105.05155
2000	105.17766
2001	105.40541
2002	105.62685
2003	105.7393
2004	105.9501
2005	106.1553
2006	106.26168
2007	106.45756
2008	106.55738
2009	106.65468
2010	106.74956
2011	106.93591
2012	107.02515
2013	107.20412
2014	107.20339
2015	107.37636