Year Percent of GDP 2004-01-01 15.0221 2005-01-01 18.5911 2006-01-01 20.9228 2007-01-01 26.6033 2008-01-01 27.4024 2009-01-01 27.4863 2010-01-01 25.6866 2011-01-01 25.1071 2012-01-01 28.8798 2013-01-01 31.1902 2014-01-01 30.1105 2015-01-01 27.7555 2016-01-01 27.1989 2017-01-01 28.3813