Year Percent of GDP 2004-01-01 4.4499 2005-01-01 5.7415 2006-01-01 14.4586 2007-01-01 29.2558 2008-01-01 33.1362 2009-01-01 30.4666 2010-01-01 27.3247 2011-01-01 25.2220 2012-01-01 25.0486 2013-01-01 25.7856 2014-01-01 25.4479 2015-01-01 24.9925 2016-01-01 26.6343 2017-01-01 29.4607