Year	Ratio
1976-01-01	0.94506
1977-01-01	0.94519
1978-01-01	0.94749
1979-01-01	0.94878
1980-01-01	0.95112
1981-01-01	0.95308
1982-01-01	0.95987
1983-01-01	0.96376
1984-01-01	0.96634
1985-01-01	0.97050
1986-01-01	0.97251
1987-01-01	0.97195
1988-01-01	0.97295
1989-01-01	0.97359
1990-01-01	0.97423
1991-01-01	0.97494
1992-01-01	0.97682
1993-01-01	0.97962
1994-01-01	0.97779
1995-01-01	0.97702
1996-01-01	0.97495
1997-01-01	0.97235
1998-01-01	0.97173
1999-01-01	0.97053
2000-01-01	0.96907
2001-01-01	0.97139
2002-01-01	0.97344
2003-01-01	0.97730
2004-01-01	0.97996
2005-01-01	0.98056
2006-01-01	0.98411
2007-01-01	0.98628
2008-01-01	0.98862
2009-01-01	0.99150
2010-01-01	0.99391
2011-01-01	0.99543
2012-01-01	0.99420
2013-01-01	0.99676
2014-01-01	0.99864
2015-01-01	0.99817
2016-01-01	0.99752