Year	Percent
1970	0.98256
1971	0.98129
1972	0.98569
1973	0.98932
1974	0.98946
1975	0.9931
1976	0.9958
1977	0.99755
1979	1.00166
1980	1.00065
1981	1.00021
1982	1.00311
1983	0.99923
1984	0.99948
1985	1.00224
1986	0.99833
1987	0.99825
1988	0.99899
1989	0.99744
1990	0.99228
1991	0.99676
1992	0.99109
1993	0.99787
1994	1.01171
1995	0.98994
1996	1.02645
1997	1.0232
1998	1.0301
1999	1.02766
2000	1.03322
2002	1.05998
2003	1.05522
2004	1.02987
2005	1.02974
2006	1.0231
2007	1.01344
2008	1.02654
2009	1.01784
2010	1.02847
2011	1.03594
2012	1.038
2013	1.042
2014	1.03812
2015	1.0359
2016	1.03782