Year	Ratio
1970-01-01	0.94663
1971-01-01	0.96745
1972-01-01	0.98175
1973-01-01	0.98232
1974-01-01	0.99673
1975-01-01	1.04046
1976-01-01	1.04093
1977-01-01	1.01494
1978-01-01	1.02122
1979-01-01	1.03965
1980-01-01	1.03692
1981-01-01	1.04674
1982-01-01	1.04485
1983-01-01	1.04933
1984-01-01	1.04717
1985-01-01	1.02923
1986-01-01	1.05337
1987-01-01	1.05428
1988-01-01	1.05723
1989-01-01	1.06096
1990-01-01	1.06810
1991-01-01	1.07405
1992-01-01	1.07109
1993-01-01	1.07404
1994-01-01	1.07546
1995-01-01	1.07701
1996-01-01	1.06891
1997-01-01	1.07078
1998-01-01	1.07133
1999-01-01	1.06428
2000-01-01	1.07137
2001-01-01	1.06587
2002-01-01	1.06641
2003-01-01	1.08378
2004-01-01	1.08037
2005-01-01	1.08202
2006-01-01	1.08199
2007-01-01	1.09417
2008-01-01	1.09647
2009-01-01	1.09164
2010-01-01	1.08293
2011-01-01	1.07937
2012-01-01	1.07114
2013-01-01	1.06756
2014-01-01	1.06269
2015-01-01	1.05496
2016-01-01	1.05545