to the statement of profit or loss in the financial year to which they relate. Once the contributions have been paid, the Group and the Company have no further payment obligations. Defined benefit plans The Group and the Company make contributions to the Group and Company’s Retirement Benefit Plan, a defined benefit plan and an approved fund independent of the Group and Company’s finances. A book provision is also provided by the Group and the Company as the contribution rate required to fund the benefits under the said plan is in excess of the Inland Revenue maximum limit. The Group and the Company also provided for a Post-Retirement Medical Plan for certain employees, which is unfunded. The liability in respect of a defined benefit plan is the present valueof the defined benefit obligation at the statement of financial position date minus the fair value of plan assets. The Group and the Company determine the present value of the defined benefit obligation and the fair value of any plan assets with sufficient regularity such that the amounts recognised in the financial statements do not differ materially from the amounts that would be determined at the end of the reporting date. The defined benefit obligation, calculated using the Projected Unit Credit Method, is determined by an independent actuarial firm, considering the estimated future cash outflows using market yields at the statement of financial position date of high-quality corporate bonds which have currency and terms to maturity approximating the terms of the related liability. The current service cost of the defined benefit plan reflects the increase in the defined benefit obligation resulting from employee services in the current year. It is recognised in the statement of profit or loss as employee benefits expense. The net interest cost is calculated by applying the discount rate to the net balance of the defined benefits obligation and the fair value of plan assets. This cost is included in employee benefit expense in the statement of profit or