Year Percent of GDP 2004-01-01 9.6587 2005-01-01 9.6092 2006-01-01 10.4117 2007-01-01 13.4196 2008-01-01 12.8007 2009-01-01 13.4545 2010-01-01 15.0617 2011-01-01 14.7917 2012-01-01 16.0119 2013-01-01 16.0202 2014-01-01 18.1155 2015-01-01 18.4220 2016-01-01 18.6234