In the application of the company's accounting policies, which are described in note 2, the directors are required to make judgements, estimates and assumptions about carrying amounts of assets and liabilities that are not readily apparent from other sources. The estimates and associated assumptions are based on historical experience and other factors which are thought to be relevent. Actual results may differ from these estimates.
The estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognised in the period in which the estimate is revised if the revision only affects that period, or in the period of revision and future periods if the revision affects both the current and future periods.