This is the third time Indiana has gotten five teams in. Nine of the ten DI schools have gotten in at least once (IPFW has only been DI since 2001), but never more than five in the same year.
EDIT: I just recounted, and Indiana did get six teams in 2000 (IU, Purdue, Butler, Valpo, ISU and Ball State), so that's one year with six and now two years with five.