Year	Ratio
1971-01-01	0.509419977664948
1972-01-01	0.522679984569550
1973-01-01	0.545409977436066
1974-01-01	0.570580005645752
1975-01-01	0.582300007343292
1976-01-01	0.585590004920959
1977-01-01	0.582220017910004
1978-01-01	0.577170014381409
1979-01-01	0.579469978809357
1980-01-01	0.597590029239655
1981-01-01	0.600350022315979
1982-01-01	0.616890013217926
1983-01-01	0.815639972686768
1984-01-01	0.824580013751984
1985-01-01	0.835839986801147
1986-01-01	0.859499990940094
1987-01-01	0.882250010967255
1988-01-01	0.892229974269867
1989-01-01	0.901120007038116
1990-01-01	0.933430016040802
1991-01-01	0.958710014820099
1992-01-01	0.979200005531311
1993-01-01	1.011919975280760
1994-01-01	1.029080033302310
1995-01-01	1.064129948616030
1996-01-01	1.041329979896550
1997-01-01	1.092470049858090
1998-01-01	1.126809954643250
1999-01-01	1.148659944534300
2000-01-01	1.183979988098140
2001-01-01	1.216940045356750
2002-01-01	1.260390043258670
2003-01-01	1.303300023078920
2004-01-01	1.373520016670230
2005-01-01	1.390140056610110
2006-01-01	1.405679941177370
2007-01-01	1.393659949302670
2008-01-01	1.385750055313110
2009-01-01	1.365370035171510
2010-01-01	1.338549971580510
2011-01-01	1.325989961624150
2012-01-01	1.328809976577760
2013-01-01	1.324790000915530
2014-01-01	1.323340058326720
2015-01-01	1.336989998817440