Year	Percent
1971	94.6649
1972	94.29379
1973	90.87
1974	91.29196
1975	92.78715
1976	96.7676
1977	104.0284
1978	104.35205
1979	104.84159
1980	103.19221
1981	96.47241
1982	91.99512
1983	93.43541
1984	98.03533
1987	100.6045
1988	98.26323
1989	96.20738
1990	96.47729
1991	96.28787
1992	100.50984
1993	106.09232
1994	104.27907
1999	100.40517
2000	99.55305
2001	102.26167
2002	102.59241
2003	106.48901
2004	104.08778
2005	100.13361
2006	95.60119
2007	95.09332
2008	94.28842
2009	93.21741
2010	96.71311
2011	101.39794
2012	102.6817
2013	102.46613
2014	101.02632
2015	103.77074