The reporting rate is the percentage of times that you answered all of the questions related to a particular measure. For individual measures, your reporting rates must be at least 50% meaning you answered the quality questions on 50% or greater of the patient records created and who were available for the measure.
The performance rate is the percentage of times you met the measure (answered "done" or "performed") compared to the number of eligible patients entered for the measure.
Performance rates of 100% are a perfect score. There are measures (i.e. Measure 1 Hemoglobin A1c) where a lower calculated performance rate is better. These are called inverse measures and a performance rate of 0% would be a perfect score.