Year current US$ 2007 15796195880 2008 16911189065.000002 2009 8741499653 2010 7052255634 2011 6421361831 2012 5472474945 2013 4694179888 2014 5102532558 2015 4250872228 2016 3966656452 2017 4404742624 2018 4515414590 2019 4563213722 2020 4419533476 2021 5489674612 2022 4490473203