Year Percent of GDP 2004-01-01 31.1616593310640 2005-01-01 34.9141276842922 2006-01-01 36.6144164077718 2007-01-01 33.1327199452807 2008-01-01 39.3090102744068 2009-01-01 31.6544190221301 2010-01-01 34.8604520294050 2011-01-01 28.0106740343009 2012-01-01 38.1577470812551 2013-01-01 42.4224362291205 2014-01-01 39.6965135438027 2015-01-01 36.6471461472576 2016-01-01 46.0405048108728 2017-01-01 40.3307383049176 2018-01-01 39.7612290333008 2019-01-01 39.6165224151024