Year	Ratio
1970-01-01	0.83041
1971-01-01	0.82970
1972-01-01	0.83116
1973-01-01	0.85740
1974-01-01	0.87987
1975-01-01	0.91086
1976-01-01	0.93732
1977-01-01	0.96470
1978-01-01	0.99369
1979-01-01	0.99801
1980-01-01	1.00699
1981-01-01	1.01766
1982-01-01	1.01265
1983-01-01	1.01535
1984-01-01	1.01313
1985-01-01	1.01163
1986-01-01	1.01588
1987-01-01	1.01726
1988-01-01	1.01320
1989-01-01	1.00908
1990-01-01	1.00673
1991-01-01	1.01025
1992-01-01	1.00958
1993-01-01	1.00562
1994-01-01	0.99935
1995-01-01	1.00704
1996-01-01	1.00605
1997-01-01	1.00962
1998-01-01	1.01511
1999-01-01	1.01172
2000-01-01	1.00713
2001-01-01	1.00849
2002-01-01	1.00118
2003-01-01	1.00424
2004-01-01	1.00966
2005-01-01	1.00819
2006-01-01	1.00013
2007-01-01	1.00172
2008-01-01	0.99756
2009-01-01	0.99813
2010-01-01	0.99418
2011-01-01	0.99014
2012-01-01	0.98993
2013-01-01	0.99322
2014-01-01	0.99250
2015-01-01	0.99122
2016-01-01	0.99182