You have commercial & residential right so if you start from there and do industry you'd add 12+21 Industry- 32 You'd go from 32 and do the next topic transportation which is 27 so youd add 27+32 Transportation-59 You'd go from 59 and do the last one electricity and add 31+59 Electricity-90 **the numbers indicate where the portion ends on the clock** Hope it helps!