There are more kinds of search engines than just internet search engines. At this point I’m is almost certain that the non-internet search engines of the world are much larger than internet search engines.

Edit: And I’m getting downvoted for this. If it’s because I am tangential to the original comment then that’s fair. If it’s because you think I’m wrong, I have worked on the two largest internet search engines in the world and one non-internet search engine that dwarfed both in size (although different in complexity).