Year	Ratio
1970-01-01	0.93229
1971-01-01	0.95683
1972-01-01	0.97360
1973-01-01	0.97360
1974-01-01	0.98916
1975-01-01	1.03721
1976-01-01	1.03717
1977-01-01	1.01061
1978-01-01	1.01785
1979-01-01	1.03760
1980-01-01	1.03486
1981-01-01	1.04493
1982-01-01	1.04389
1983-01-01	1.04873
1984-01-01	1.04660
1985-01-01	1.02726
1986-01-01	1.05303
1987-01-01	1.05404
1988-01-01	1.05716
1989-01-01	1.06101
1990-01-01	1.06828
1991-01-01	1.07588
1992-01-01	1.07237
1993-01-01	1.07440
1994-01-01	1.07592
1995-01-01	1.07752
1996-01-01	1.06890
1997-01-01	1.07047
1998-01-01	1.07121
1999-01-01	1.06468
2000-01-01	1.07264
2001-01-01	1.06700
2002-01-01	1.06769
2003-01-01	1.08591
2004-01-01	1.08231
2005-01-01	1.08413
2006-01-01	1.08383
2007-01-01	1.09726
2008-01-01	1.09880
2009-01-01	1.09356
2010-01-01	1.08423
2011-01-01	1.08054
2012-01-01	1.07159
2013-01-01	1.06862
2014-01-01	1.06357
2015-01-01	1.05559
2016-01-01	1.05603