Table:
| As of December 31, | 2019 | 2018 | 2017 | 2016 | 2015 |
| --- | --- | --- | --- | --- | --- |
| Working capital (1) | $207,599 | $237,416 | $306,296 | $226,367 | $219,219 |
| Total assets | $545,118 | $628,027 | $669,094 | $667,235 | $632,904 |
| Total debt (2) | $24,600 | $25,600 | $26,700 | $27,800 | $28,900 |
| Stockholders’ equity | $380,426 | $446,279 | $497,911 | $479,517 | $480,160 |
Paragraphs:
BALANCE SHEET DATA
(In thousands)
(1) Working capital consists of current assets less current liabilities. Amounts prior to 2016 have been recast to conform to the current period’s presentation as a result of our adoption of Accounting Standards Update 2015-17, Balance Sheet Classification of Deferred Taxes. See Note 1 of Notes to Consolidated Financial Statements, included in Part II, Item 8 of this report for additional information.
(2) Total debt outstanding consisted of taxable revenue bonds due to the State of Alabama Industrial Development Authority. The bonds matured on January 1, 2020 and were repaid in full on January 2, 2020. See Note 12 of Notes to Consolidated Financial Statements, included in Part II, Item 8 of this report for additional information.
Question:
What does total debt outstanding consist of?
Answer: taxable revenue bonds due to the State of Alabama Industrial Development Authority.