The share refers to patients, and they are unduplicated for individual health centers but not if a patient visited more than one health center. For example, if a patient goes to both Site 1 and Site 2 of Health Center A, the patient will only be counted once by that health center. However, if the patient goes to Health Center A and Health Center B, both health centers are reporting the patient as one patient from the same ZCTA. Since there is no way for us to know that each health center counted the patient, overall in the data the patient would be counted twice.