The demand function for services is : P = -0.5Q + 80 The marginal cost and also the average cost of providing this service is 9. At first there is perfect competition in this market. But it then turns into such a thing that one company achieves exclusive selling status on it (monopoly status). (the sole trader is assumed to maximize his profit) What is the welfare loss in this change from perfect competition to exclusive selling? Enter the answer to one decimal place.