This is not advice but rather scores you need for each rank. It should give you something to go by when going for each one.
F- 0-499
F 500-1499
F+ 1500-2499
E- 2500-3499
E 3500-4499
E+ 4500-5499
D- 5500-6499
D 6500-7499
D+ 7500-8499
C- 8500-9499
C 9500-10499
C+ 10500-12499
B- 12500-14499
B 14500-16499
B+ 16500-26499
A- 26500-36499
A 36500-46499
A+ 46500-96499
S 96500-196499
SS 196500-99999999