You are taxing my brain, lol. Define co-champion: regular season conference record the same as other team(s) OR splitting regular season conference championship with other team that won conference tournament? For example, in 2004 we won sole possession of regular season conference championship, but we lost the Big Ten tourney championship to WI. Therefore, we would have one banner up. In 2005, we won outright the regular season conference championship and the Big Ten Tourney Championship. I honestly don't know whether we got a banner to hang for each of those.