Year	current US$
2009	3158524179.55347
2010	7353937474.72876
2011	16551429341.5148
2012	18559179349.1826
2013	18649230028.5503
2014	17741949149.8825
2015	17230571097.1822
2016	12949945352.0072
2017	13252537238.2771
2018	14676299760.1522
2019	17321970893.3437