Year	Ratio
1971-01-01	0.094140000641346
1972-01-01	0.121919997036457
1973-01-01	0.144620001316071
1974-01-01	0.164949998259544
1975-01-01	0.192369997501373
1976-01-01	0.281720012426376
1977-01-01	0.322210013866425
1978-01-01	0.312040001153946
1979-01-01	0.358139991760254
1980-01-01	0.388190001249313
1981-01-01	0.446649998426437
1982-01-01	0.490049988031387
1983-01-01	0.538739979267120
1984-01-01	0.620500028133392
1985-01-01	0.659060001373291
1986-01-01	0.722920000553131
1987-01-01	0.797219991683960
1991-01-01	1.070719957351680
1992-01-01	0.854449987411499
1993-01-01	1.012779951095580
1994-01-01	0.895370006561279
1995-01-01	0.907720029354095
1996-01-01	0.902100026607513
1997-01-01	0.880689978599548
1998-01-01	1.117720007896420
1999-01-01	1.223989963531490
2000-01-01	1.288779973983760
2001-01-01	1.227079987525940
2002-01-01	1.318480014801030
2003-01-01	1.485589981079100
2004-01-01	1.526010036468510
2005-01-01	1.477679967880250
2006-01-01	1.454200029373170
2007-01-01	1.284489989280700
2008-01-01	1.281589984893800
2009-01-01	1.271520018577580
2010-01-01	1.149940013885500
2011-01-01	1.089050054550170
2012-01-01	1.012470006942750
2013-01-01	0.963649988174438
2014-01-01	0.990100026130676
2015-01-01	1.009809970855710
2016-01-01	1.002930045127870