Normal questions show the date they were asked and the date of the last edit.
Community wiki questions don't show the date they were asked on; only the date of the last edit.
To find the creation date, one must click the "last edited" link, then scroll all the way down.
I think the creation/asking date of the question is way more important than "who" has the largest edit percentage. Plus, it helps to know whether a question has been asked a year ago or a week ago.