Table:
|  | 2015 2 | 2016 3 | 2017 4 | 2018 4,5 | 2019 4 |
| --- | --- | --- | --- | --- | --- |
| Adjusted EBITDA | $3,206 | $3,743 | $4,149 | $4,725 | $4,917 |
| Cash Taxes | (107) | (98) | (137) | (172) | (168) |
| Maintenance Capex | (124) | (159) | (115) | (150) | (160) |
| Corporate Capex | (26) | (27) | (17) | (9) | (11) |
| Numerator | $2,948 | $3,459 | $3,880 | $4,394 | $4,579 |
| Gross PPE | $14,397 | $15,652 | $16,950 | $17,717 | $19,326 |
| Gross Intangibles | 12,671 | 14,795 | 16,183 | 16,323 | 18,474 |
| Gross Goodwill6 | 4,240 | 4,510 | 4,879 | 4,797 | 5,492 |
| Denominator | $31,308 | $34,957 | $38,012 | $38,837 | $43,292 |
| ROIC | 9.4% | 9.9% | 10.2% | 11.3% | 10.6% |
Paragraphs:
American Tower Corporation • 2019 Annual Report
Appendix 1 • Letter to Stakeholders
RETURN ON INVESTED CAPITAL (ROIC) RECONCILIATION1 ($ in millions. Totals may not add due to rounding.)
1 Historical denominator balances reflect purchase accounting adjustments
2 Represents Q4 2015 annualized numbers to account for full year impact of Verizon Transaction.
3 Represents Q4 2016 annualized numbers to account for full year impact of Viom Transaction
4 Adjusted to annualize impacts of acquisitions closed throughout the year.
5 Positively impacted by the Company's settlement with Tata in Q4 2018.
6 Excludes the impact of deferred tax adjustments related to valuation.
Question:
How many years did gross intangibles exceed $15,000 million?
Answer: Objects satisfying the requirements:
2017
2018
2019
As a result, the answer is 3