Year	Ratio
1970-01-01	0.88447
1971-01-01	0.91661
1972-01-01	0.89862
1973-01-01	0.89922
1974-01-01	0.89019
1975-01-01	0.88931
1976-01-01	0.89800
1977-01-01	0.90594
1978-01-01	0.91483
1979-01-01	0.91957
1980-01-01	0.94227
1981-01-01	0.93607
1982-01-01	0.95202
1983-01-01	0.96922
1984-01-01	0.97974
1985-01-01	1.00690
1986-01-01	1.03079
1987-01-01	1.04347
1988-01-01	1.06140
1989-01-01	1.07193
1990-01-01	1.07776
1991-01-01	1.08132
1992-01-01	1.10523
1993-01-01	1.10590
1994-01-01	1.14099
1995-01-01	1.19410
1996-01-01	1.21071
1997-01-01	1.21956
1998-01-01	1.27558
1999-01-01	1.28919
2000-01-01	1.33716
2001-01-01	1.39676
2002-01-01	1.45399
2003-01-01	1.43984
2004-01-01	1.42150
2005-01-01	1.41600
2006-01-01	1.39012
2007-01-01	1.41541
2008-01-01	1.42086
2009-01-01	1.40806
2010-01-01	1.41093
2011-01-01	1.40433
2012-01-01	1.43537
2013-01-01	1.46006
2014-01-01	1.45293
2015-01-01	1.45573
2016-01-01	1.46228