He had 19 in '88 good for about half of his matches.
Not necessarily on topic, but these statistics were right next to that one, Coach John won 90.7% of his matches in '87 by bonus. He wasn't quite as dominant in '88 winning 83% by bonus. Pretty ridiculous especially since he wouldn't even have won one of his matches in '87.
Metcalf didn't top the 90% bonus rate in his statistically best season, 2008-2009. I would guess Askren might have, but I doubt too many others have.