KOSMOS ENERGY LTD. Notes to Consolidated Financial Statements (Continued) 12. Equity-based Compensation (Continued) The following table reflects the outstanding restricted stock units as of December 31, 2017: Weighted- Market / Service Weighted- Service Vesting Average Vesting Average Restricted Stock Grant-Date Restricted Stock Grant-Date Units Fair Value Units Fair Value (In thousands) (In thousands) Outstanding at December 31, 2014: . . . . 3,367 $ 10.76 3,246 $ 15.66 Granted . . . . . . . . . . . . . . . . . . . . . . 1,539 8.37 3,544 12.96 Forfeited . . . . . . . . . . . . . . . . . . . . . (254) 10.14 (212) 14.48 Vested . . . . . . . . . . . . . . . . . . . . . . . (1,060) 10.71 — — Outstanding at December 31, 2015: . . . . 3,592 9.79 6,578 14.24 Granted . . . . . . . . . . . . . . . . . . . . . . 2,158 4.05 1,379 4.88 Forfeited . . . . . . . . . . . . . . . . . . . . . (134) 8.87 (70) 14.49 Vested . . . . . . . . . . . . . . . . . . . . . . . (1,456) 9.61 (693) 15.81 Outstanding at December 31, 2016: . . . . 4,160 6.91 7,194 12.29 Granted . . . . . . . . . . . . . . . . . . . . . . 2,085 6.43 2,175 9.50 Forfeited . . . . . . . . . . . . . . . . . . . . . (137) 6.91 (21) 6.21 Vested . . . . . . . . . . . . . . . . . . . . . . . (1,925) 7.51 (896) 15.43 Outstanding at December 31, 2017: . . . . 4,183 6.39 8,452 11.26 As of December 31, 2017, total equity-based compensation to be recognized on unvested restricted stock awards and restricted stock units is $23.6 million over a weighted average period of 1.5 years. For restricted stock awards and restricted stock units with a combination of market and service vesting criteria, the number of common shares to be issued is determined by comparing the Company’s total shareholder return with the total shareholder return of a predetermined group of peer companies over the performance period and can vest up to 100% of the awards granted for restricted stock awards and up to 200% of the awards granted for restricted stock units. The grant date fair value of these awards ranged from $6.70 to $13.57 per award for restricted stock awards and $4.83 to $15.81 per award for restricted stock units. The Monte Carlo simulation model utilizes multiple input variables that determine the probability of satisfying the market condition stipulated in the award grant and calculates the fair value of the award. The expected volatility utilized in the model was estimated using our historical volatility and the historical volatilities of our peer companies and ranged from 41.3% to 56.7% for restricted stock awards and 44.0% to 54.0% for restricted stock units. The risk-free interest rate was based on the U.S. treasury rate for a term commensurate with the expected life of the grant was 0.5% for restricted stock awards and and ranged from 0.5% to 1.4% for restricted stock units. For profit units that were exchanged for restricted stock awards, the significant assumptions used to calculate the fair values of the profit units granted as calculated using a binomial tree, were as follows: no dividend yield, expected volatility ranging from approximately 25% to 66%; risk-free interest rate ranging from 1.3% to 5.1%; expected life ranging from 1.2 to 8.1 years; and projected turnover rates ranging from 7.0% to 27.0% for employees and none for management. For profit units granted immediately prior to our initial public offering, we utilized the midpoint of the range of the estimated offering price, or $17.00 per share. 140