Table:
| Number of shares (1,000) | 2019 | 2018 | 2017 |
| --- | --- | --- | --- |
| Outstanding as of 1 January | 2,719.1 | 2,611.2 | 1,999.8 |
| Granted during the period | 1,001.1 | 907.3 | 866.6 |
| Exercised during the period | -529.4 | - | - |
| Expired during the period | -785.3 | -764.0 | -233.9 |
| Forfeited during the period | -177.2 | -35.4 | -21.3 |
| Outstanding as of 31 December | 2,228.3 | 2,719.1 | 2,611.2 |
| Exercisable as of 31 December | - | 255.3 | 255.3 |
Paragraphs:
Long-term employee benefit obligations
The obligation comprises an obligation under the incentive programs to deliver Restricted Share Units in TORM plc at a determinable price to the entity's key personnel. The RSUs granted entitle the holder to acquire one TORM A-share.
The program was established during the year and comprises the following number of shares in TORM plc:
In 2017, the Board agreed to grant a total of 866.6 RSUs to other management. The RSUs to other management were subject to a three-year vesting period, with one third of the grant amount vesting at each anniversary date beginning on 1 January, 2018. The exercise price of each vested RSU is following certain adjustments for dividends at DKK 93.6 and an exercise period of six months.
In 2018, the Board agreed to grant a total of 944,468 RSU’s to other management. The vesting period of the program is three years for key employees and three years for the Executive Director. The exercise price is set to DKK 53.7. The exercise period is 12 months after the vesting date for key employees and 12 months after the vesting date for the Executive Director. The fair value of the options granted in 2018 was determined using the Black-Scholes model and is not material. The average remaining contractual life for the restricted shares as per 31 December 2018 is 1.1 years (2017: 1.3 years).
In 2019, the Board agreed to grant a total of 1,001,100 RSUs to other management. The vesting period of the program is three years for key employees. The exercise price is set to DKK 53.7. The exercise period is 12 months after the vesting date. The fair value of the options granted in 2019 was determined using the Black-Scholes model and is not material. The average remaining contractual life for the restricted shares as per 31 December 2019 is 1.5 years.
Question:
How was the fair value of the options determined?
Answer: Black-Scholes model