Year Percent of GDP 2004-01-01 22.7895 2005-01-01 20.4566 2006-01-01 21.4837 2007-01-01 22.0988 2008-01-01 28.1039 2009-01-01 29.6428 2010-01-01 29.6004 2011-01-01 30.3201 2012-01-01 31.1518 2013-01-01 31.2708 2014-01-01 31.6480 2015-01-01 33.3067 2016-01-01 35.2678 2017-01-01 36.8004