Year	Ratio
1971-01-01	0.1014399975538250
1973-01-01	0.1164800003170970
1974-01-01	0.1769299954175950
1975-01-01	0.1372700035572050
1977-01-01	0.0951400026679039
1978-01-01	0.0957399979233742
1980-01-01	0.0976999998092651
1981-01-01	0.1052900031208990
1984-01-01	0.1502999961376190
1985-01-01	0.1639599949121480
1986-01-01	0.1519200056791310
1987-01-01	0.1839700043201450
1988-01-01	0.2142399996519090
1989-01-01	0.2486000061035160
1990-01-01	0.2265200018882750
2001-01-01	0.4689300060272220
2002-01-01	0.4707899987697600
2003-01-01	0.5194799900054930
2004-01-01	0.5704200267791750
2009-01-01	0.7728599905967710
2010-01-01	0.7828099727630620
2011-01-01	0.7540500164031980
2012-01-01	0.8083299994468690
2013-01-01	0.7868199944496150
2014-01-01	0.8301699757575990
2015-01-01	0.7768899798393250
2016-01-01	0.7635800242424010