Year Percent of GDP 2004-01-01 20.7510 2005-01-01 21.9428 2006-01-01 22.5369 2007-01-01 28.0102 2008-01-01 29.2555 2009-01-01 31.0315 2010-01-01 34.7531 2011-01-01 34.6862 2012-01-01 33.5326 2013-01-01 35.0319 2014-01-01 37.8534 2015-01-01 41.4501 2016-01-01 40.9579