Each lot went to 1 or more states. The authors are stating that the lots that went to 13 or more states had the vast majority of adverse events. If all of the lots are the same size (the author suggests 1000 vial lots = 6000 doses) then this is a big problem. The lots that were producing most all of the adverse events were spread between the most states. A logical conclusion is that the people distributing the lots were carefully dividing the "bad" or perhaps active lots between as many states as possible to avoid detection while the "safe" lots were divided between fewer states.

Each lot went to 1 or more states. The authors are stating that the lots that went to 13 or more states had the vast majority of adverse events. If all of the lots are the same size (the author suggests 1000 vile lots = 6000 doses) then this is a big problem. The lots that were producing most all of the adverse events were spread between the most states. A logical conclusion is that the people distributing the lots were carefully dividing the "bad" or perhaps active lots between as many states as possible to avoid detection while the "safe" lots were divided between fewer states.