caesari's got it -- values actually contain decimals and what you see is the nearest whole-number depiction. So if your "average" potential was, say 7.15 points of growth, the guy might have improved by 0.25...which wouldn't necessarily trigger an increase in his rating number (69.9 and 70.15 would both show as 70, for instance), but the improvement would be enough to bump the color code from average growth remaining down to low growth potential.