See below from a Globe article in May. WTKK's ratings, overall, are at radioandrecords and of course these are only 12+, and they don't break it down show to show--though the Globe article does give us more info.
From the Globe back in May: "According to Arbitron, the libertarian loudmouth (Severin) is drawing an impressive audience in his new 7-10 p.m. time slot on WTKK-FM (96.9). In fact, Severin's has become the highest rated show on the station, shellacking both morning man Don Imus and the guy who replaced Severin in drive time, Michael Graham."
It goes on: "the station's spinning the latest ratings to make it look like Graham is the big winner. ''[He's] really beginning to catch on. . . . His natural talent, background and energy make him a great listen," Greater Media's Phil Redo gabbed in a statement. ''[Graham's] just warming up.' What he didn't say is that it's rare for a night-time jock to drub the morning and drive-time guys."--(BG 5/9/06; showed up in Yahoo search
for "Severin ratings")