You can only retake boards if you fail (not sure if you are saying that). Step 1 is taken between second and third year of med school (usually before you start rotations), and probably what the schools are talking about when listing passing percentages listed by med schools, so I'm not sure repeating "intern year" is really what people are talking about by board scores here...
The boards are very much an individual effort -- I wouldn't use this as a means to compare schools. Additionally, since almost all US allo schools have over 90% first time pass rates, the passing rate isn't a great yardstick.