Year Percent of GDP 2004-01-01 15.6975 2005-01-01 18.3757 2006-01-01 20.1699 2007-01-01 23.3236 2008-01-01 26.3562 2009-01-01 26.8228 2010-01-01 27.3550 2011-01-01 27.1731 2012-01-01 28.3938 2013-01-01 28.1240 2014-01-01 27.1726 2015-01-01 26.0082 2016-01-01 26.3097 2017-01-01 28.4154