I guess India is somewhat worse, but you get the idea.
If someone leaked that there is an absence of corruption then that would news worthy, but such false information doesn't seem to be the kind of articles Wikileaks would publish. Logically, if you can't publish about the existence of corruption because everyone knows about it and you can't publish about the absence of corruption because it would be false, then Russian coverage regarding corruption will be lackluster. Maybe they should just post a bunch of empty pages with the title "Russia corruption" to make statistics like the parent posted look better.
I may very well be able to do that, but it wouldn't do anything to disprove the notion that Wikileaks has a pro- Russian, anti-US bias.
I see two simple reasons for the lack of Russian coverage at Wikileaks: either Russians aren't providing material, or Assange isn't publishing it.
Movies and TV shows like to use corruption in Russia as a stereotypical movie plot, but that makes it less news worthy for news papers. If there isn't a large interest from readers then there is no ad revenues to be gained, and no interest for journalist to write about it.
Of course one could be conspiratorial and accuse all the large media companies to be pro-Russia or having a curios set of priorities, but I find the simple answer to be more likely. tptacek conspiracy theory need to eliminate those simple answers before I will consider it anything more than a political view.