Detailed Commentary on Sections in Part 6 Schedule 1: Alteration of Assembly Electoral Regions Paragraph 9(2)
613.However, if the total number of regional seats cannot be divided exactly by 5 (for example, 19), the next highest number which can be divided exactly by 5 is identified (for example, if the total number of regional seats was 19, that next highest number would be 15.)
614.This is then subtracted from the total number of regional seats (in the above example, 15 would be subtracted from 19, leaving 4).