Year Percent of GDP 2004-01-01 13.5202 2005-01-01 13.9097 2006-01-01 18.4159 2007-01-01 18.1476 2008-01-01 18.0810 2009-01-01 21.8525 2010-01-01 22.4872 2011-01-01 23.1645 2012-01-01 23.8112 2013-01-01 24.0528 2014-01-01 24.1556 2015-01-01 24.4318 2016-01-01 24.8904