A+=100%, 1 gallon, 20 house points
A=90%-99%, 15 sickles, 18 house points
B+=80%-89%, 13 sickles, 16 house points
B=70%-79%, 11 sickles, 14 house points
C+=60%-69%, 9 sickles, 12 house points
C=50%-59%, 7 sickles, 10 house points
D+=40%-49%, 5 sickles, 8 house points
D=30%-39%, 3 sickles, 6 house points
F=0%-29%, -5 knuts, -5 house points