| Summary of stock based awards |
| | | | | | | | | | | | | | | | | Options | | Shares | | | Weighted average exercise price | | | Weighted average remaining term | | | Aggregate fair value | | Outstanding as of December 31, 2017 | | | 790,458 | | | $ | 29.8 | | | | 3.80 | | | $ | 7,539 | | Vested at December 31, 2017 | | | 136,011 | | | | — | | | | — | | | | — | | Exercisable at December 31, 2017 | | | 136,011 | | | | — | | | | — | | | | — | | Forfeited or expired | | | (128,481 | ) | | | — | | | | — | | | | (1,843 | ) | Granted | | | — | | | | — | | | | — | | | | — | | Outstanding as of December 31, 2018 | | | 661,977 | | | $ | 28.2 | | | | 3.36 | | | $ | 5,696 | | Vested at December 31, 2018 | | | 116,667 | | | | — | | | | — | | | | — | | Exercisable at December 31, 2018 | | | 116,667 | | | | — | | | | — | | | | — | | Forfeited or expired | | | (132,209 | ) | | | — | | | | — | | | | (682 | ) | Outstanding as of December 31, 2019 | | | 529,768 | | | | 26.6 | | | | 2.96 | | | | 5,014 | | Vested at December 31, 2019 | | | 83,333 | | | | — | | | | — | | | | — | | Exercisable at December 31, 2019 | | | 83,333 | | | | — | | | | — | | | | — | | Forfeited or expired | | | (67,475 | ) | | | — | | | | — | | | | (1,199 | ) | Outstanding as of December 31, 2020 | | | 462,293 | | | | 17.9 | | | | 2.25 | | | | 3,815 | | Restricted stock and restricted stock units | | | | | | | | | | | | | | | | | Non Vested as of December 31, 2017 | | | 701,731 | | | $ | — | | | | 3.09 | | | $ | 9,059 | | Granted | | | 287,500 | | | | — | | | | — | | | | 863 | | Vested | | | (279,071 | ) | | | — | | | | — | | | | (3,425 | ) | Forfeited or expired | | | (450 | ) | | | — | | | | — | | | | (7 | ) | Non Vested as of December 31, 2018 | | | 709,710 | | | $ | — | | | | 3.11 | | | $ | 6,490 | | Granted | | | 167,515 | | | | — | | | | — | | | | 476 | | Vested | | | (180,469 | ) | | | — | | | | — | | | | (1,595 | ) | Forfeited or expired | | | (3,367 | ) | | | — | | | | — | | | | (42 | ) | Non Vested as of December 31, 2019 | | | 693,389 | | | $ | — | | | | 2.32 | | | $ | 5,329 | | Granted | | | — | | | | — | | | | — | | | | — | | Vested | | | (309,664) | | | | — | | | | — | | | | (2,858 | ) | Forfeited or expired | | | (1,345) | | | | — | | | | — | | | | (17 | ) | Non Vested as of December 31, 2020 | | | 382,380 | | | $ | — | | | | 1.72 | | | | 2,453 | |
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