Year current US$ 2011 42.54884888507486 2012 110.84880451244786 2013 125.99461039034827 2014 175.1601043117422 2015 149.61454540875582 2016 143.41360662101798 2017 204.8408422034192 2018 151.7508488668324 2019 160.47986360287933 2020 171.84810717135224 2021 197.1675038496886 2022 190.33434321556516