Year current US$ 2008 568992956.076299 2009 564543239.849428 2010 454357295.220905 2011 681475902.285392 2012 852491367.612354 2013 977688265.342749 2014 602991889.858844 2015 585886256.138558 2016 881736265.030113 2017 1209949425.23659 2018 1266975399.50309 2019 1297036620.71105 2020 1058278079.44149 2021 1319266532.69889