Consolidated Natural Gas Company (CNG), with corporate headquarters in Pittsburgh, Pennsylvania, is one of the largest producers, transporters, distributors, and marketers of natural gas in North America.

Periodically, the company experiences a decrease in the value of its gas- and oil-producing properties, and a special charge to income was recorded in order to reduce the carrying value of those assets.

Assume the following information. In 2016, CNG estimated the cash inflows from its oil- and gas-producing properties to be $375,000 per year. During 2017, the write-downs described above caused the estimate to be decreased to $275,000 per year. Production costs (cash outflows) associated with all these properties were estimated to be $125,000 per year in 2016, but this amount was revised to $155,000 per year in 2017.