What is an average reader/commenter rate for a news or blog article?

Quite an ambiguous question, I know.
But probably you guys have the websites with a good traffic so that you could share the average numbers with us?

This rate seems to be changing with the time and growing with the readers growth.
Would be extremely interesting to see the distribution.

I'm sure the number varies widely depending on the site, but there is a generally agreed upon concept known as the 90-9-1 principle. From wikipedia :

In Internet culture, the 1% rule or the 90–9–1 principle (sometimes also presented as 89:10:1 ratio) reflects a theory that more people will lurk in a virtual community than will participate. This term is often used to refer to participation inequality in the context of the Internet.

The 1% rule states that the number of people who create content on the internet represents approximately 1% (or less) of the people actually viewing that content (for example, for every person who posts on a forum, there are generally about ninety-nine other people viewing that forum but not posting).

I think this is more of an orders-of-magnitude principle, and isn't really based on any specific data. Your mileage may vary.