Year Percent of GDP 2004-01-01 30.9989 2005-01-01 29.2440 2006-01-01 27.9445 2007-01-01 30.3644 2008-01-01 29.7410 2009-01-01 31.2189 2010-01-01 29.0513 2011-01-01 28.2613 2012-01-01 28.3583 2013-01-01 28.6452 2014-01-01 29.9479 2015-01-01 29.8144 2016-01-01 29.7652 2017-01-01 29.4600