Year current US$ 2011 7292054957.87379 2012 8582345644.98488 2013 8045351656.98449 2014 12050030642.6416 2015 12259111044.8115 2016 15654910566.3545 2017 17143758244.488 2018 20146977655.1481 2019 19822066132.838 2020 20747482882.7848 2021 19751974014.9667