And Chester Alan Arthur ought to be ranked higher than "average". At least higher than Clinton. Arthur came in on a fluke: Garfield's assassination. Everyone thought he was going to be a corrupt administrator, and he wasn't. He rose to the occasion.
Impeached42, otoh, came in promising, "the most ethical administration ever", and he was rotten to the core.
Arthur may have risen to the occasion in some sense, but he is still one of only two sitting presidents of less than two terms who was NOT renominated by his party (the other was Fillmore, btw). Not exactly a favourable verdict of his presidency from his colleagues, eh?