Year Percent of GDP 2004-01-01 16.9142 2005-01-01 16.7291 2006-01-01 17.9563 2007-01-01 19.5130 2008-01-01 20.1985 2009-01-01 21.3181 2010-01-01 21.9606 2011-01-01 22.5807 2012-01-01 23.8466 2013-01-01 27.8914 2014-01-01 28.8282 2015-01-01 26.5541 2016-01-01 31.7631