Do you mean GPA? If so, the question is irrelevant if you have been working for more than a couple of years. For recent college grads, I would be truthful. "I was working full time and supporting a family" or "I took the most difficult courses to challenge myself". You might not want to say you partied too much or was bored with college. All that shows is immaturity. Unless you think you can convince them that you have put all of that behind you. Good luck.