Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
|  | Twelve Months Ended December 31, | Twelve Months Ended December 31, | Twelve Months Ended December 31, | Twelve Months Ended December 31, |
| --- | --- | --- | --- | --- |
|  | 2018 | 2018 | 2017 | 2017 |
|  | Dollars | Cost/Gal | Dollars | Cost/Gal |
| Raw or "into-plane" fuel cost | $1,938 | $2.31 | $1,437 | $1.80 |
| (Gain)/loss on settled hedges | (24) | (0.03) | 17 | 0.02 |
| Consolidated economic fuel expense | $1,914 | $2.28 | $1,454 | $1.82 |
| Mark-to-market fuel hedge adjustments | 22 | 0.03 | (7) | — |
| GAAP fuel expense | $1,936 | $2.31 | $1,447 | $1.82 |
| Fuel gallons | 839 |  | 797 |  |
Question:
What was the GAAP fuel expense per gallon in 2018 for Alaska Airlines ?
Answer:
$2.31