Year Percent of GDP 2004-01-01 4.4407 2005-01-01 8.6702 2006-01-01 19.5332 2007-01-01 31.6317 2008-01-01 21.9122 2009-01-01 21.8791 2010-01-01 23.5300 2011-01-01 24.1135 2012-01-01 27.0209 2013-01-01 27.4696 2014-01-01 28.4274 2015-01-01 28.6871 2016-01-01 29.1053 2017-01-01 29.1053