Year Percent of GDP 2004-01-01 15.5146 2005-01-01 17.5701 2006-01-01 16.9539 2007-01-01 18.6220 2008-01-01 15.7199 2009-01-01 16.7469 2010-01-01 16.1033 2011-01-01 13.8783 2012-01-01 12.9103 2013-01-01 13.1553 2014-01-01 16.2671 2015-01-01 15.4828 2016-01-01 18.5028