Year Billions of U.S. Dollars 2015-01-01 -8500000 2016-01-01 -11700000 2017-01-01 -7600000 2018-01-01 -8800000 2019-01-01 -13500000 2020-01-01 -14600000 2021-01-01 -14500000 2022-01-01 -14900000 2023-01-01 -14100000