Year Percent of GDP 2004-01-01 17.5538 2005-01-01 15.5541 2006-01-01 16.7001 2007-01-01 17.5082 2008-01-01 18.2731 2009-01-01 18.8323 2010-01-01 18.3389 2011-01-01 18.7898 2012-01-01 18.8617 2013-01-01 17.2810 2014-01-01 17.3528 2015-01-01 19.0808 2016-01-01 20.1032 2017-01-01 23.4690