Table:
|  |  | Years Ended December 31, |  |
| --- | --- | --- | --- |
|  | 2019 | 2018 | 2017 |
| Number of shares of common stock granted | 16 | 16 | 13 |
| Weighted average grant-date fair value per common stock | $29.10 | $28.48 | $30.49 |
| Fair value of common stock vested | $320 | $315 | $334 |
| Cash used to settle the obligation | $366 | $804 | $1,134 |
Paragraphs:
The following table summarizes information regarding shares of common stock granted and vested (in thousands, except per common stock amounts):
As of December 31, 2019, there was $0.2 million of total unrecognized compensation cost, net of actual forfeitures, related to nonvested common stock. This cost is expected to be recognized over a weighted average period of 4.2 years.
Question:
In which year was the Weighted average grant-date fair value per common stock the smallest?