Year	Percent
1971	0.9296
1972	0.93709
1973	0.9508
1974	0.9494
1975	0.98067
1976	0.98517
1977	0.99126
1978	0.99337
1979	0.97509
1980	1.02029
1981	1.02226
1982	0.9989
1983	1.03307
1984	1.01847
1985	1.02075
1986	1.0391
1987	1.04703
1988	1.03937
1989	1.03779
1990	1.02986
1991	1.03872
1992	1.04542
1993	1.04824
1994	1.04964
1995	1.05089
1996	1.05504
1997	1.03131
1998	1.03575
1999	1.03495
2000	1.03408
2001	1.03148
2002	1.03445
2003	1.0285
2004	1.0319
2005	1.02956
2006	1.02814
2007	1.03033
2008	1.02795
2009	1.02129
2010	1.00988
2011	1.00337
2012	1.00187
2013	1.00775
2014	1.00762
2015	1.00436
2016	1.00904