Year	Ratio
1970-01-01	0.910000026226044
1971-01-01	0.996399998664856
1975-01-01	0.919110000133514
1976-01-01	0.922760009765625
1977-01-01	0.923409998416901
1978-01-01	0.923579990863800
1980-01-01	0.952859997749329
1981-01-01	0.958949983119965
1982-01-01	0.963500022888184
1983-01-01	0.962580025196075
1984-01-01	0.964089989662170
1985-01-01	0.964320003986359
1986-01-01	0.965730011463165
1987-01-01	0.963930010795593
1988-01-01	0.966310024261475
1989-01-01	0.968810021877289
1990-01-01	0.967369973659515
1991-01-01	0.967149972915649
1992-01-01	0.968029975891113
1993-01-01	0.972500026226044
1994-01-01	0.971360027790070
1995-01-01	0.970770001411438
1996-01-01	0.975149989128113
1998-01-01	0.978900015354156
2001-01-01	0.984319984912872
2002-01-01	0.988080024719238
2003-01-01	0.994419991970062
2004-01-01	1.066130042076110
2005-01-01	0.994459986686707
2006-01-01	0.990849971771240
2007-01-01	0.987940013408661
2008-01-01	0.986230015754700
2009-01-01	0.981930017471313
2010-01-01	0.975000023841858
2011-01-01	0.960290014743805
2012-01-01	0.976369976997375
2013-01-01	0.976149976253510
2014-01-01	0.977469980716705
2015-01-01	0.979309976100922
2016-01-01	0.979110002517700