Year current US$ 2008 2124185 2009 3758510 2010 1799982 2011 22798634 2012 1661438 2013 10904212 2014 9982917 2015 1894041 2016 2978941 2017 1071740 2018 1169092 2019 4008678 2020 1317536 2021 4624983 2022 2421297