One of my Sites is a known poor performer, but is reporting a low ratio (or vice versa).

If one of your sites looks like it ranks incorrectly, you may have entered incorrect square footage, space usages, occupancy hours, % heated/cooled, consumption units (therms vs. __). Another cause may be that you have meters incorrectly connected to sites. You may be missing a meter that services that building or may have an extra meter that really services another building.