Year Percent of GDP 2004-01-01 16.2119 2005-01-01 16.9169 2006-01-01 20.1099 2007-01-01 17.9839 2008-01-01 18.4811 2009-01-01 19.7697 2010-01-01 20.9683 2011-01-01 18.5243 2012-01-01 17.7792 2013-01-01 17.0097 2014-01-01 17.0986 2015-01-01 16.6824 2016-01-01 16.9338