Year current US$ 2008 1186.3806873118906 2009 1258.1995065357096 2010 1317.08185108031 2011 1364.8041179645081 2012 1524.0303184783968 2013 1654.9748655895107 2014 1748.527313725403 2015 1640.0979695486756 2016 1461.8927936296045 2017 1314.7211507489283 2018 1340.77905587732 2019 1418.2721860593836 2020 1356.232246413521 2021 1393.6767687327617 2022 1468.5759602876667 2023 1463.6300347318522