A local government office issues hunting licences. Demand for these licences is relatively slow in the first part of the year but then increases after the middle of the year before slowing down again towards the end of the year. The department works a 220-day year on a five-days-a-week basis. Between working days 0 and 100, demand is 25 per cent of demand during the peak period which lasts between day 100 and day 150. After day 150 demand reduces to about 12 per cent of the demand during the peak period. In total, the department processes 10,000 applications per year. The department has two permanent members of staff who are capable of processing 15 licence applications per day. If an untrained temporary member of staff can process only ten licences per day, how many temporary staff should the department recruit between days 100 and 150?