Year	Ratio
1970-01-01	0.78857
1971-01-01	0.78998
1972-01-01	0.79361
1973-01-01	0.78849
1974-01-01	0.78695
1975-01-01	0.78444
1976-01-01	0.78079
1977-01-01	0.78956
1978-01-01	0.78895
1979-01-01	0.78471
1980-01-01	0.78192
1981-01-01	0.77093
1982-01-01	0.78551
1983-01-01	0.78052
1984-01-01	0.78130
1985-01-01	0.78232
1986-01-01	0.76552
1987-01-01	0.76185
1988-01-01	0.77618
1989-01-01	0.78108
1990-01-01	0.78578
1991-01-01	0.79608
1992-01-01	0.80745
1993-01-01	0.81906
1994-01-01	0.82144
1995-01-01	0.83403
1996-01-01	0.83547
1997-01-01	0.85578
1998-01-01	0.87407
1999-01-01	0.89835
2000-01-01	0.91095
2001-01-01	0.91464
2002-01-01	0.94110
2003-01-01	0.94054
2004-01-01	0.95268
2005-01-01	0.96941
2006-01-01	0.99189
2007-01-01	0.99989
2008-01-01	1.00810
2009-01-01	1.00984
2010-01-01	1.01064
2011-01-01	1.01290
2012-01-01	1.04086
2013-01-01	1.06104
2014-01-01	1.07663
2015-01-01	1.08041
2016-01-01	1.09047