Year % of GDP 2008 18.3494320395115 2009 16.9333041532624 2010 33.1545986311909 2011 37.5995095680529 2012 33.5831339945811 2013 32.456213802314 2014 30.5605456602098 2015 31.3334204840025 2016 30.9383540538056 2017 29.182559454284