Year current US$ 2004 241.17110443985652 2005 309.92683292848255 2006 436.8344264546377 2007 610.909947662228 2008 838.8135475291247 2009 743.9752465701613 2010 770.8971708319974 2011 887.7562936559809 2012 1041.751042369474 2013 1132.0129567218646 2014 1183.3769544162783 2015 1044.262519408457 2016 856.2215845583805 2017 913.4044312423582 2018 897.033456864227 2019 909.4644333745689 2020 869.1688292570243 2021 928.7859714964609