Year % of GDP 2008 15.6349638124866 2009 18.8664531280369 2010 23.1822093203965 2011 29.1875975591087 2012 29.8802036939277 2013 31.5157197972696 2014 31.7196750455138 2015 34.5905104475229 2016 33.1797335526042 2017 32.7555783491497