Year Percent 2005-01-01 1.12306816304321 2006-01-01 1.15671810199409 2007-01-01 1.21278135248144 2008-01-01 1.23379459796547 2009-01-01 1.66868361287220 2010-01-01 1.61471958167627 2011-01-01 1.61569510529058 2012-01-01 1.59155879776141 2013-01-01 1.61812893230912 2014-01-01 1.55006600303062 2015-01-01 1.44346035749462 2016-01-01 1.28023853020411 2017-01-01 1.17273381138342