Year Percent of GDP 2004-01-01 8.1364 2005-01-01 8.8733 2006-01-01 9.1179 2007-01-01 9.6095 2008-01-01 10.4996 2009-01-01 11.3271 2010-01-01 12.7321 2011-01-01 13.8371 2012-01-01 14.3641 2013-01-01 14.7238 2014-01-01 15.5576 2015-01-01 16.3142