Year current US$ 2012 622613.489627838 2013 593050.718307495 2014 473140.001296997 2015 477259.993553162 2016 483709.990978241 2017 528500.020503998 2018 245291.20326042201 2019 172429.993748665 2020 352463.036775589 2021 520600.020885468 2022 713774.800300598