Year Percent of GDP 2004-01-01 20.6707 2005-01-01 18.5914 2006-01-01 19.9652 2007-01-01 22.3782 2008-01-01 22.1163 2009-01-01 24.2420 2010-01-01 26.2816 2011-01-01 27.3299 2012-01-01 28.5396 2013-01-01 32.0760 2014-01-01 33.4134 2015-01-01 36.5327 2016-01-01 38.2334