E. Movement in net defined benefit assets (liabilities) and in their components:
| Fair value of plan assets | Defined benefit obligation | Defined benefit obligation, net | |||
| 2017 | 2016 | 2017 | 2016 | 2017 | 2016 |
| $ millions | $ millions | $ millions | $ millions | $ millions | $ millions |
Actuarial losses deriving from changes in financial assumptions | ||||||