Year Percent of GDP 2004-01-01 4.6712 2005-01-01 7.2410 2006-01-01 11.2016 2007-01-01 16.9819 2008-01-01 18.8192 2009-01-01 19.5264 2010-01-01 19.0244 2011-01-01 18.3529 2012-01-01 17.4509 2013-01-01 16.1002 2014-01-01 15.1815 2015-01-01 15.0780 2016-01-01 14.7412 2017-01-01 15.8838