Table:
|  |  |  | (dollars in millions) |
| --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 |
| Balance at January 1, | $ 2,871 | $2,355 | $ 1,902 |
| Additions based on tax positions related to the current year | 149 | 160 | 219 |
| Additions for tax positions of prior years | 297 | 699 | 756 |
| Reductions for tax positions of prior years | (300) | (248) | (419) |
| Settlements | (58) | (40) | (42) |
| Lapses of statutes of limitations | (89) | (55) | (61) |
| Balance at December 31, | $ 2,870 | $ 2,871 | $ 2,355 |
Paragraphs:
A reconciliation of the beginning and ending balance of unrecognized tax benefits is as follows:
Included in the total unrecognized tax benefits at December 31, 2019, 2018 and 2017 is $2.4 billion, $2.3 billion and $1.9 billion, respectively, that if recognized, would favorably affect the effective income tax rate.
Question:
What was the average Additions for tax positions of prior years for 2017-2019?
Answer: (297 + 699 + 756) / 3 = 584