Year U.S. dollars (Billions) 2011 17.340 2012 11.267 2013 14.947 2014 15.178 2015 15.326 2016 2.899 2017 1.804 2018 3.118 2019 4.044 2020 5.423 2021 5.940 2022 8.037 2023 7.295 2024 6.517 2025 6.987 2026 7.324 2027 7.789 2028 8.514 2029 9.702