Year current US$ 2003 3418000000 2007 6907000000 2008 6775000000 2009 6744000000 2010 7536000000 2011 9317000000 2012 8400000000 2013 8690000000 2014 9263000000 2015 11183000000 2016 13438000000 2017 15020000000 2018 16974000000 2019 19849000000 2020 5960000000