IAS 16 Revaluation.

Hi, i am facing problem in the transfer of excess depreciation. If a PPE cost $100 with useful life of 10 years it has depreciation of $10 each year. After one year from acquisition it got revalued to $180 with the change of life of 12 years we get revaluation surplus of $90 ($180-$90). Then should i transfer excess dep of Revaluation surplus / remaining life (90/12=7.5) or difference between after revalued dep and historical dep (15-10=5) ?