The calculation is performed annually by a qualified actuary using the projected unit credit
method. When the calculation results in a benefit to the Group, the recognised asset is limited to
the present value of economic benefits available in the form of any future refunds from the plan
or reductions in future contributions to the plan. In order to calculate the present value of
economic benefits, consideration is given to any minimum funding requirements that apply to
any plan in the Group. An economic benefit is available to the Group if it is realisable during the
life of the plan, or on settlement of the plan liabilities