Year Percent of GDP 2004-01-01 15.3937 2005-01-01 17.2782 2006-01-01 18.3947 2007-01-01 25.6113 2008-01-01 35.2845 2009-01-01 39.5856 2010-01-01 19.5372 2011-01-01 19.3527 2012-01-01 19.8162 2013-01-01 20.6762 2014-01-01 19.9650 2015-01-01 18.1668 2016-01-01 17.8649