Round B raise -- Dilution to founders?

I saw Indochino raised a $13.5 mill round B (http://techcrunch.com/2013/03/28/indochin/) recently. Their round A was last year which was around $4 mill.
I was wondering if raising another round in such a short period will increase dilution to the owners share more so than if they raised a round B next year.

Also, after 2 rounds of financing, what % do you think the founders still hold?
I remember learning that it is in the VC's best interest that the owners hold >20% so the founders don't lose their interest and move their attention to a side project.