In 1991, Abraham Company completed the construction of a building at a cost of P1,900,00 and first occupied it in January 1992. It was estimated that the building will have a useful life of 40 years and a residual value of P60,000 at the end of that time.

Early in 2002, an addition to the building was constructed at a cost of P470,000. At that time it was estimated that the remaining life of the building would be, as originally estimated, and additional 30 years, and that the addition would have a life of 30 years, and a residual value of P20,000.

In 2020, it is determined that the probable life of the building and addition will extend to the end of 2051 or 20 years beyond the original estimate.

a) Using the straight-line method, compute the annual depreciation that would have been charged from 1992 - 2001.

b) Compute the annual depreciation that would have been charged from 2002 - 2019.

c) Compute the annual depreciation to be charged beginning 2020.