Year Percent of GDP 2015-01-01 18.5775 2016-01-01 18.9972 2017-01-01 18.8294 2018-01-01 18.9012 2019-01-01 18.7256 2020-01-01 18.5561 2021-01-01 17.8103 2022-01-01 16.7671 2023-01-01 15.9867