Judgements and key sources of estimation uncertaintyThe preparation of the financial statements requires management to make judgements, estimates and assumptions that affect the amounts reported. These estimates and judgements are continually reviewed and are based on experience and other factors, including expectations of future events that are believed to be reasonable under the circumstances.Income taxThe taxation expense represents the aggregate amount of current and deferred tax recognised in the reporting period. Tax is recognised in profit or loss, except to the extent that it relates to items recognised in other comprehensive income or directly in equity. In this case, tax is recognised in other comprehensive income or directly in equity, respectively.Current tax is recognised on taxable profit for the current and past periods. Current tax is measured at the amounts of tax expected to pay or recover using the tax rates and laws that have been enacted or substantively enacted at the reporting date.Deferred tax is recognised in respect of all timing differences at the reporting date. Unrelieved tax losses and other deferred tax assets are recognised to the extent that it is probable that they will be recovered against the reversal of deferred tax liabilities or other future taxable profits. Deferred tax is measured using the tax rates and laws that have been enacted or substantively enacted by the reporting date that are expected to apply to the reversal of the timing difference.