Year Percent of GDP 2004-01-01 15.0413 2005-01-01 15.0905 2006-01-01 14.7354 2007-01-01 14.3064 2008-01-01 14.3445 2009-01-01 15.4240 2010-01-01 15.3246 2011-01-01 15.2918 2012-01-01 15.6435 2013-01-01 15.9147 2014-01-01 15.9991 2015-01-01 16.1491 2016-01-01 16.3082 2017-01-01 17.2130