My guess is that NC probably had a odd number of seniors who only needed a couple credits to graduate, so they went to class less than 4 hours a day.
A. Enrollment Calculation Formulas 1. Fulltime students, students receiving an average of four (4) hours or more of instruction
per day, shall be counted as one (1) student each. Students attending school less than
fulltime, students receiving less than four (4) hours of instruction per day, shall be counted
as a half (1/2) student each.