Year	Ratio
1973-01-01	0.97445
1974-01-01	0.96797
1975-01-01	0.95373
1976-01-01	0.94275
1977-01-01	0.94794
1978-01-01	0.94970
1979-01-01	0.92846
1980-01-01	0.92523
1981-01-01	0.90214
1982-01-01	0.90503
1983-01-01	0.91209
1984-01-01	0.91890
1985-01-01	0.90308
1986-01-01	0.88021
1987-01-01	0.88001
1988-01-01	0.87297
1989-01-01	0.87983
1990-01-01	0.88352
1991-01-01	0.88881
1992-01-01	0.90481
1993-01-01	0.91931
1994-01-01	0.91709
1995-01-01	0.93098
1996-01-01	0.93974
1997-01-01	0.96562
1998-01-01	0.99049
1999-01-01	1.01854
2000-01-01	1.03850
2001-01-01	1.03799
2002-01-01	1.05425
2003-01-01	1.05741
2004-01-01	1.07978
2005-01-01	1.08677
2006-01-01	1.10363
2007-01-01	1.13330
2008-01-01	1.15646
2009-01-01	1.16071
2010-01-01	1.16849
2011-01-01	1.17939
2012-01-01	1.18175
2013-01-01	1.18523
2014-01-01	1.18463
2015-01-01	1.19584
2016-01-01	1.20389