Zombies:  a 1 long wall; a 0.1 wide hole in the wall; for 1 hour, every second a zombie arrives in a completely random position of the wall; the distribution (in 5 s intervals) of the waiting times between a pass of a zombie and the next pass 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 138, 103, 50, 40, 26, 8, 8, 6, 0, 2 Unitary percentage frequencies:

between 0 and 5 s, 7.24% of passages per second, ... The curve:  y = 0.1·e−0.1·x   (remarks)