Year current US$ 2009 18492514 2010 11301002 2011 8259133 2012 10978416 2013 14208170 2014 13835438 2015 5765833 2016 6875574 2017 5350848 2018 6498091 2019 34843264 2020 4097238.9999999995 2021 3595403 2022 3443803