Year Percent of GDP 2004-01-01 9.54474500005742 2005-01-01 10.19878584360670 2006-01-01 10.43818195145860 2007-01-01 11.90418415296560 2008-01-01 12.09761763252510 2009-01-01 12.05053247299240 2010-01-01 12.01999095469970 2011-01-01 12.28141853128280 2012-01-01 12.74861222136260 2013-01-01 13.12488955381080 2014-01-01 13.25930762025440 2015-01-01 13.68242996802100 2016-01-01 14.72212677825690 2017-01-01 15.03670296131260 2018-01-01 15.04134441321420 2019-01-01 15.21231714659350