Year	Ratio
1970-01-01	0.70778
1971-01-01	0.70921
1972-01-01	0.71284
1973-01-01	0.73045
1974-01-01	0.75336
1975-01-01	0.76191
1976-01-01	0.76954
1977-01-01	0.78325
1978-01-01	0.79614
1979-01-01	0.79975
1980-01-01	0.80487
1981-01-01	0.82036
1982-01-01	0.83816
1983-01-01	0.87287
1984-01-01	0.88886
1985-01-01	0.89706
1986-01-01	0.91457
1987-01-01	0.92675
1988-01-01	0.93904
1989-01-01	0.95404
1990-01-01	0.97244
1991-01-01	0.98164
1992-01-01	1.01157
1993-01-01	1.03356
1994-01-01	1.05236
1995-01-01	1.09210
1996-01-01	1.11428
1997-01-01	1.14541
1998-01-01	1.16491
1999-01-01	1.17115
2000-01-01	1.18140
2001-01-01	1.19811
2002-01-01	1.21723
2003-01-01	1.22454
2004-01-01	1.23733
2005-01-01	1.24400
2006-01-01	1.25351
2007-01-01	1.25777
2008-01-01	1.26204
2009-01-01	1.26315
2010-01-01	1.26318
2011-01-01	1.26088
2012-01-01	1.25153
2013-01-01	1.24324
2014-01-01	1.23626
2015-01-01	1.23535
2016-01-01	1.23322