> I can understand 0 and 1 being frequently used. But I wonder why 5,6 & 7 seem to be under-used compared to the other numbers? The heat map isn't accounting f

> I can understand 0 and 1 being frequently used. But I wonder why 5,6 & 7 seem to be under-used compared to the other numbers? The heat map isn't accounting for shift. 5,6,7 also include %,^,&