Year	Ratio
2005-01-01	36.8594174105269
2006-01-01	39.2228106246356
2007-01-01	41.2492230837737
2008-01-01	41.9470982893145
2009-01-01	43.8386869612044
2010-01-01	59.5201108459623
2011-01-01	59.2269551075167
2012-01-01	58.7264280381108
2013-01-01	59.0542868640850
2014-01-01	56.6658636787679
2015-01-01	56.1272050842727
2016-01-01	55.5015990724441
2017-01-01	54.0336041900720