Visitor profile summary: avarage time on each page

Visitor profile summary: having the average time on each page would be really interesting, because it tells you something about the "deep" of the interest of this visitor.

Please see attachment.

(This is maybe even more interesting than average loading time across different pages and within different visits.Loading times varies independently of a special visitor during a day/night cycle because of server load and the more visits the more these value moves in the direction of the total average across all sites and across all visitors..)