Year Percent of GDP 2004-01-01 2.9351 2005-01-01 3.7050 2006-01-01 4.5076 2007-01-01 7.1774 2008-01-01 9.4476 2009-01-01 9.9561 2010-01-01 10.8185 2011-01-01 12.8238 2012-01-01 13.3319 2013-01-01 14.8907 2014-01-01 17.0693 2015-01-01 15.7685 2016-01-01 15.6562