Year current US$ 2007 444602326.814094 2008 511381018.068047 2009 435374730.581266 2010 432777941.711782 2011 481041750.548784 2012 365401000.282385 2013 398633378.931761 2014 355214107.509146 2015 333603924.062667 2016 423358562.650147 2017 406324405.991975 2018 527820430.815929 2019 548336315.561317 2020 437764604.15059 2021 459364500.413535