2012:03: March Conundrum: Getting Lucky

March Madness is heating up!  This year, 68 teams enter the infamoussingle-elimination tournament, but only one prevails.  As a Notre Dame fan, you’re rooting for the Fightin’ Irish to come out on top.  And this time you have compelling evidence pointing to the fact that they will!  At one point in the season, the Irish had a 50% winning percentage.  Just when it counted, they went on a tear to finish the regular season with a 90% winning record—unbelievable!  As you prepare to fill out your NCAA bracket, you’re doing some statistics from the season and you discover a curious fact.  There are several othernice, round winning percentages that your ND Irish also hit during the season.  That is, there were other guaranteed winning record fractions (wins to total games) that the Fightin’ Irish obtained during the regular season.  Can you figure out what they were?