Shelby Axelle is a mechanic at Chromium Mechanics Inc. Shelby is responsible for the maintenance of 20 trucks in a fleet. These trucks require maintenance and/or break down once every 12 days. It usually takes Shelby 5 hours to fix everything on any given truck. What is the probability that less than 16 trucks are operating (i.e. not in the system)? (Assume 8 hours in a workday for Shelby; Answer in percentage form to two decimal points, but exclude the "%" symbol from your answer)