These actually are everything but "predicting" stats.
In a nutshell, the numbers are the number of searches for that particular term (be it a keyword, a multiple word term or a domain name with or without extension) that were done on Overture in the last month.
It does not have anything to do with how many people visited your site or how many people might visit your site - it's just about the number of searches on OVT.
Of course there is a certain likeliness that if there have been many searches for your domain (with extension, i.e "yourdomain.com") or the exact term of your domain (without extension, i.e. "yourdomain" or "your domain") there will a certain number of typeins to your domain but that's just guessing.
Also keep in mind that OVT often mixes up the order of words within a search term as well as mixing up plural and singular which means it might show a term like "registration domain" when in reality the term that was actually searched for was "domain registration" so never base your domain buying decision on OVT stats alone.