Year Percent of GDP 2004-01-01 18.7672 2005-01-01 19.3952 2006-01-01 23.9488 2007-01-01 23.9857 2008-01-01 24.4912 2009-01-01 28.7355 2010-01-01 30.7152 2011-01-01 32.6303 2012-01-01 33.9377 2013-01-01 34.8417 2014-01-01 35.3325 2015-01-01 36.3747 2016-01-01 37.4948