Year	constant 2015 US$
2008	7981369404.1886015
2009	7131680787.819646
2010	8015005958.709231
2011	7803680648.786143
2012	5052795472.555495
2013	5591711574.331675
2014	5876888864.622589
2015	3467364408.1904445