On Virtual University website, an excel sheet is availabble. They applied this formula
=ROUND((IF(E7>=80,4,IF(AND(E7<80,E7>=65),3+(E7-65)/15,IF(AND(E7<65,E7>=50),2+(E7-50)/15,IF(AND(E7<50,E7>=40),1+(E7-40)/10,0))))),2)
According to this formula, 70% means 3.33
Is it correct?