The results are from all voting centers. Once a voting center finishes counting, it sends it to the data center. So the data are sent more or less randomly to t

The results are from all voting centers. Once a voting center finishes counting, it sends it to the data center. So the data are sent more or less randomly to the data center. You are right that this does not mean that are truly representative. But for the sake of simplicity we can call it "representative".