Year	Ratio
1970-01-01	0.65004
1971-01-01	0.65091
1972-01-01	0.66115
1973-01-01	0.69173
1974-01-01	0.71269
1975-01-01	0.73025
1976-01-01	0.73431
1977-01-01	0.77265
1978-01-01	0.79579
1979-01-01	0.81773
1980-01-01	0.83770
1981-01-01	0.85883
1982-01-01	0.87040
1983-01-01	0.87922
1984-01-01	0.88886
1985-01-01	0.89955
1986-01-01	0.91051
1987-01-01	0.92669
1988-01-01	0.94504
1989-01-01	0.96278
1990-01-01	0.99419
1991-01-01	1.00103
1992-01-01	1.02392
1993-01-01	1.03080
1994-01-01	1.03898
1995-01-01	1.05858
1996-01-01	1.06382
1997-01-01	1.07099
1998-01-01	1.08140
1999-01-01	1.08563
2000-01-01	1.09018
2001-01-01	1.10131
2002-01-01	1.12806
2003-01-01	1.14283
2004-01-01	1.15781
2005-01-01	1.16829
2006-01-01	1.17612
2007-01-01	1.17996
2008-01-01	1.18405
2009-01-01	1.18796
2010-01-01	1.19097
2011-01-01	1.19150
2012-01-01	1.18907
2013-01-01	1.17439
2014-01-01	1.16697
2015-01-01	1.16447
2016-01-01	1.16371