Year Percent of GDP 2004-01-01 16.2964 2005-01-01 21.3113 2006-01-01 25.6538 2007-01-01 29.8221 2008-01-01 33.9864 2009-01-01 35.5572 2010-01-01 41.2942 2011-01-01 44.5600 2012-01-01 45.6342 2013-01-01 51.9293 2014-01-01 54.7276 2015-01-01 57.2891 2016-01-01 60.1437 2017-01-01 72.1661