People with type O-negative blood are universal donors. That is, any patient can receive a transfusion of O-negative blood. Suppose only 6.8% of the American population have O-negative blood. If 9 people appear at random to give blood, what is the probability that none of them is a universal donor? (Assume that the events that random people have type O-negative blood are independent events.) (Round your answer to two decimal places.)