Q3: A building that was acquired on December 31, 2000, for $2,500,000 was originally estimated to have a life of 50 years with no residual value. Depreciation expenses have been recorded till the end of 2019. During 2020, an examination of the building by an engineering firm reveals that its estimated useful life is only 15 years after 2019.

Based on the above, how to record the depreciation entries at the end of year 2015 and 2025, under the use of straight-line method?