Year Percent of GDP 2004-01-01 4.2504 2005-01-01 4.9668 2006-01-01 5.1849 2007-01-01 6.2806 2008-01-01 7.8694 2009-01-01 7.9064 2010-01-01 8.1309 2011-01-01 8.8142 2012-01-01 9.7661 2013-01-01 10.6163 2014-01-01 11.4784 2015-01-01 12.4773 2016-01-01 12.2352 2017-01-01 13.0031