I've got my primitive little gizmo digesting the entire UFO topic in Chat, the one in Bloggers, and three keywords (UFO UFOS UAP). It's, uh, kinda big. Once the sort's finished the duplicates will be out and after a brief visual check I'll run the counter thing to see how many over the years. :^)
2471 topics. The midpoint is sometime in 2011, oldest one listed here is from 2001. Some are actually about Kuchinich, other liberal nutjobs. :^)