Year Percent of GDP 2004-01-01 16.0730 2005-01-01 19.4410 2006-01-01 22.1125 2007-01-01 23.1900 2008-01-01 21.6487 2009-01-01 27.1011 2010-01-01 27.5232 2011-01-01 24.1019 2012-01-01 24.2167 2013-01-01 24.0814 2014-01-01 26.4920 2015-01-01 27.2942 2016-01-01 28.1519 2017-01-01 30.2944