Year current US$ 2007 3416666 2008 4747147 2009 6979502 2010 11226657 2011 696891 2012 1128720 2013 376541 2014 1101491 2015 5860647 2016 4340427 2017 4292150 2018 6243919 2019 6637323 2020 11992939 2021 14531924