Hard to draw any kind of real analysis there given the relatively tiny number of people who are attacked to begin with and the even tinier subset who have a weapon period...and then the significantly smaller portion of those that OC (I don't have the numbers but given the laws in most states I'm guessing CC'ers outnumber OC'ers a hundredfold or more).
You needn't infer a conclusion from the data available but neither should you dismiss it as unreal or even hard analysis.
How many OCing citizens do you hear about being attacked on the news in the last few years. How many CCers? How many unarmed? Do those match the percentages of the people that carry or don't carry in that area, or do only two of the numbers match their relative percentage while one group is victimized at a much lower rate than even their relatively smaller subgroup size would suggest?
You know the media would love to paste it in the headlines, so I doubt underreporting is to blame.