text: The graph has time on the X-axis. For this exercise, the interval does not matter except to note that data are equally spaced in time. The Y-axis has a dimensionless model score and is integral. It can increment by 0, 2 or 4 units at a time (like no change= 0, some change =2 units, much change = 4 units.) The dark dots are the arithmetic average of each time slice.