In a small village of size 85, four individuals contacted a contagious disease. Thirteen have already caught, recovered and are now immune from the disease. Each individual meets others at an average rate of six per day. At each contact between an infective and a susceptible, the disease is transmitted with a probability of 0.05. On catching the disease, an individual becomes infectious immediately, remaining so for an average time of one week. At the end of the infectious period, recovery is instantaneous.

At the end of the epidemic, how many individuals are expected not to have caught the disease (give your answer to two decimal places)?