In order to gain residency credit in the second or third year of legal study, the student must enroll in at least 12 units per semester and must pass (grade of "D" or better) at least 9 of those units per semester. Where the student fails to pass at least 9 units in a particular semester, s/he will receive only fractional residency credit for that semester represented by the number of units actually passed over a constant denominator of 9. For instance, if a student undertakes 12 units but receives the letter grade "F" in 5 of those 12 units, that student will receive 7/9th of a semester's residency for that particular semester.