The Group uses EBITDA as an alternative performance measure ("APM") to explain and judge its performance. The Directors consider EBITDA to be a useful measure of the Group's operating performance because it approximates the underlying operating cash flow.

The Group defines EBITDA as earnings before interest, taxation, depreciation of property, plant and equipment, amortisation of intangible assets, impairment of intangible assets, property, plant and equipment, and exceptional items.

As EBITDA is not defined under IFRS, it is described as a 'non-GAAP' measure.

A reconciliation from operating profit, the most directly comparable IFRS measure to EBITDA, is shown below the consolidated income statement.