At the bank teller's window, arrivals and service times are randomly distributed (Poisson and exponential distributions, respectively). There is only one teller at the window. If the arrival rate is 8 customers per hour, and the service rate is 15 customers per hour, what is the utilization of the teller, as a percentage? (It is a single channel, single server, single phase, unlimited waiting space model).

(calculate answer to two decimal places)