Year current US$ 2011 50896912885.7158 2012 58623848241.1957 2013 61325446003.1774 2014 62842274545.4357 2015 36651997223.2357 2016 31362269362.8302 2017 37345690739.8795 2018 45872745489.1882 2019 36683876955.7856 2020 25433300108.1684 2021 45182286030.9546