Year	current US$
2008	5846597710.98767
2009	6249435944.56771
2010	16425057822.3279
2011	22551180460.3644
2012	20128990867.7504
2013	19561273739.5774
2014	20000715769.0357
2015	18702107432.2377
2016	19570422383.484
2017	19470336599.6169