Year current US$ 2006 385750812.592607 2007 219055401.662427 2008 323733423.425163 2009 280535146.156007 2010 411228664.768474 2011 581461817.249483 2012 730116842.682108 2013 302735182.563871 2014 423536773.045141 2015 304795681.483575 2016 501289025.062301 2017 529916877.816867 2018 399316252.120044 2019 512140262.786979 2020 382971781.518465 2021 302160135.484634