Year constant 2015 US$ 2009 541.6153917208494 2010 538.2009605750374 2011 511.1845056198302 2012 501.5443066146957 2013 286.8898071773452 2014 277.185989967576 2015 293.402626903364 2016 330.0047464673923 2017 311.30284745442725 2018 377.4617913111648 2019 372.39335963881507 2020 357.0092689912606 2021 347.3378649206266