Year Percent of GDP 2004-01-01 18.0281 2005-01-01 18.8758 2006-01-01 20.4863 2007-01-01 23.6405 2008-01-01 24.9349 2009-01-01 26.7290 2010-01-01 27.9166 2011-01-01 29.2006 2012-01-01 31.3740 2013-01-01 32.3948 2014-01-01 33.1396 2015-01-01 34.2135 2016-01-01 35.4159 2017-01-01 38.0786