Year	Percent
1971	0.96163
1972	0.968
1973	0.97428
1974	0.9798
1975	0.96351
1976	0.97467
1977	0.97904
1978	0.99003
1979	0.99885
1980	1.01186
1981	1.0107
1982	1.02259
1983	1.02552
1984	1.02096
1985	1.01942
1986	1.0141
1987	1.01759
1988	1.01157
1989	1.00878
1990	1.01096
1991	1.01182
1992	1.01303
1993	1.00918
1994	1.00581
1995	1.00364
1996	1.0073
1997	1.01171
1999	1.01296
2000	1.01198
2001	1.00584
2002	1.01154
2003	1.01033
2004	1.01149
2005	1.00908
2006	1.00742
2007	1.00612
2008	1.00065
2009	1.00186
2010	1.00617
2011	1.00435
2012	1.00855
2013	1.0033
2014	1.00446
2015	0.99619