Before entering into a discussion of 'why no data' on other denominations, allow me to ask a question, first. Were we to produce such data, would you then accuse us of 'trying to make ourselves feel better?'
You see, you've placed us in something of a 'darned if we do, darned if we don't' situation. On the one hand we present data showing abuse in other sectors of society and you attack us for it. When we then give legitimate reasons for producing the data, you then demand more data on how other denominations handled abuse, thus setting us up for another attack.
Can you see how some might question your motives given this method of argumentation?