15. Twenty-five years ago, tofu was available only from small businesses operating in predominantly Asian sections of large cities. Today tofu has become popular as a high-protein health food and is widely available in supermarkets throughout the United States. At the same time, tofu production has evolved to become factorybased using modern food-processing technologies. Draw a diagram with demand and supply curves depicting the market for tofu 25 years ago and the market for tofu today. Given the information above, what does the demand-supply model predict about changes in the volume of tofu sold in the United States between then and now? What does it predict about changes in the price of tofu?