Year	current US$
2008	31294243695.5098
2009	38042453492.7554
2010	44826960838.6505
2011	55313954372.4118
2012	55886410036.5806
2013	58951563961.4754
2014	64880388349.6703
2015	61370769577.8
2016	65254544403.9083
2017	69396527178.2063