pre_text: A tax credit of £8.9m in the year compared to a £13.7m charge in the prior year. This included a deferred tax credit in the current year of £6.1m, largely reflecting the loss before tax reported of £42.7m and a credit of £1.7m relating to the adjustment of prior period losses and capital allowances. A current year tax credit of £1.1m was in respect of overseas tax. A deferred tax liability at 30 March 2019 of £13.5m compared to a liability of £12.1m at 31 March 2018. This movement is primarily due to a slightly higher pensions surplus reported at 30 March 2019 compared to 31 March 2018 reflecting the allowability for tax on pensions contribution payments. Recognised and unrecognised deferred tax assets relating to brought forward losses were approximately £44m at 30 March 2019 and equate to around £250m of future taxable profits. The corporation tax rate and deferred tax rate applied in calculations are 19.0% and 17.0% respectively.
table: £m 2018/19 2017/18 Change
table: Overseas current tax
table: Current year 1.1 0.8 0.3
table: Deferred tax
table: Current period 6.1 (4.1) 10.2
table: Prior periods 1.7 (8.1) 9.8
table: – Adjustment to restate opening deferred tax at 17.0% – (2.3) 2.3
table: Income tax credit/ (charge) 8.9 (13.7) 22.6
question: Analyse this data from a financial earnings document. What was the average deferred tax for 2017/18 and 2018/19?