Year Percent of GDP 2004-01-01 23.1239 2005-01-01 23.2226 2006-01-01 15.0962 2007-01-01 14.1868 2008-01-01 15.6708 2009-01-01 14.8467 2010-01-01 15.8104 2011-01-01 17.1639 2012-01-01 18.6887 2013-01-01 20.0081 2014-01-01 20.9205 2015-01-01 20.7290 2016-01-01 19.3239 2017-01-01 19.7831