Year Percent of GDP 2004-01-01 17.9930 2005-01-01 18.4905 2006-01-01 19.2635 2007-01-01 19.4524 2008-01-01 20.4388 2009-01-01 22.4423 2010-01-01 22.6531 2011-01-01 23.3574 2012-01-01 23.6263 2013-01-01 23.9561 2014-01-01 24.2294 2015-01-01 24.1101 2016-01-01 24.3809 2017-01-01 25.2281