Year Percent of GDP 2004-01-01 12.9810 2005-01-01 16.1183 2006-01-01 17.6062 2007-01-01 17.7974 2008-01-01 17.3910 2009-01-01 18.2483 2010-01-01 18.2178 2011-01-01 17.6082 2012-01-01 16.0023 2013-01-01 16.4037 2014-01-01 18.1422 2015-01-01 18.1618 2016-01-01 18.9020