Enterprise has a year end of 31 December.It purchased a building for $50 million on 1 January 2016 and attributed it a useful economic life of 50 years.Enterprise classified the building as PPE and accounted for it using the revaluation model.

On 31 December 2017,the fair value of the building was deemed to be

$53 million.The total useful economic life of the building remained unchanged.

By 31 December 2018,there was a collapse in property prices.The fair value of the building was deemed to be $44 million.

Enterprise does not transfer for the excess depreciation arising from a revaluation, from reserves.

Discuss how this transaction should have been accounted for each reporting year.