Year Percent of GDP 2004-01-01 12.7931 2005-01-01 13.9141 2006-01-01 14.3896 2007-01-01 15.5640 2008-01-01 18.1470 2009-01-01 12.7925 2010-01-01 16.1896 2011-01-01 15.1233 2012-01-01 14.2415 2013-01-01 14.7347 2014-01-01 15.4806 2015-01-01 15.9536 2016-01-01 16.1324