A+ (97% and more), A (from 93% to 96%), A- (from 90% to 92%), B+ (from 87% to 89%), B (from 83% to 86%), B- (from 80% to 82%), C+ (from 77% to 79%), C (from 73% to 76%), C- (from 70% to 72%), D+ (from 67% to 69%), D (from 63% to 66%), D- (from 60% to 62%), n/a (from 0% to 59%).