Splogi, or Phobia search by interest

Gentlemen, will anyone tell me if someone keeps statistics on the share of splogs in the total mass of blogs, within RuNet or in general around the world?

I've been doing a search for interests here several times, and slightly ofarel. On Blog.ru, if you choose to search for any popular interest (tag)

blog.ru/people/interests <- assign interest to the link, for example, “life”
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in response, the stream of porn-splogs, with rare patches of human blogs, falls out. Here I was wondering if someone keeps statistics on this scourge?