I wonder what the percentage means. upvote/flag ratio?
Good guess, but no. It's a score generated by the ring detector. It's rather out of date, because the code has changed a lot since that computation was written.
I built a clone at news.intelmap.com a year or two ago, and I don't have the percentages in my admin console. Perhaps an addition since pg's exit?
I'm guessing it's the ratio of older user upvotes vs total upvotes.