According to one of Japan's largest paper manufacturers, growing demand for toilet paper stockpiles in case of natural disasters has led to a prolonged spike in sales, the Yomiuri Shimbun newspaper reports . "So why is toilet paper use going up when the number of people using it is supposedly going down?" the paper asks, pointing to the aftermath of the 2011 earthquake in which toilet paper disappeared from the shelves of shops for the answer. The temporary shortage led to the government to urge people to hold at least one month's supply in their homes, with one housewife telling the paper that she had enough toilet paper in her home to stretch 3.9km (2.4 miles): "They don't go bad, so knowing that we have them on hand is a relief," she said. The recommended stockpile is 15 rolls, the paper says.