Intelligence modifier

Score  Modifier 1      -5 2-3     -4 4-5     -3 6-7     -2 8-9     -1 10-11    0 12-13   +1 14-15   +2 16-17   +3 18-19   +4 20-21   +5 22-23   +6 24-25   +7

Says Xilinx