Year current US$ 2007 5195605 2008 7247588 2009 5130103 2010 4727601 2011 7448895 2012 7581095 2013 9332592 2014 9307631 2015 11860132 2016 21845447 2017 28235636 2018 36293329 2019 45573710 2020 26514439 2021 37562645 2022 476798137