Year Percent of GDP 2007-01-01 16.7883 2008-01-01 15.9007 2009-01-01 17.3011 2010-01-01 15.3500 2011-01-01 16.3002 2012-01-01 17.9034 2013-01-01 19.2526 2014-01-01 20.2357 2015-01-01 22.2592 2016-01-01 22.8957