Estimated changes are handled prospectively. They require no adjustments to previously issued financial statements. These changes are accounted for in the period of the change, or if more than one period is affected, in both the period of change and in the future. For example, assume that a company originally estimated that an asset would have a useful service life of 10 years, and after 3 years of service the total service life of the asset was estimated to be only 8 years. The remaining book value of the asset would be depreciated over the remaining useful life of five years. The effects of changes in estimates on operating income, extraordinary items, and the related per-share amounts must be disclosed in the year they occur. As with accounting changes to LIFO, the added disclosures should aid users in their judgments regarding comparability.