"PC31 said 'we caught a dirty one' " is a line from the Beatles song Maxwell's Silver Hammer. Presumably PC31 joined the force before PC36, but after PC25 and PC21, assuming, of course, that badge numbers were assigned in numerical sequence, and the size of the force in question was small. I'm certain that the weight of the constables did not correlate to their badge numbers nor order of induction, and depending on the size of the force itself they may have all been inducted simultaneously. The weight assigned to each constable by his superiors certainly varied and may as well have affected his performance in the field, but in no way hindered their ability to fly. (That's one minute of your life you'll never get back.)