there's a list with various serial numbers and their dates in one of these threads, if i remember correctly, it was posted by rod trussbroken, although i'm not completely sure of that. hope that helps
I have more pre EB serial and intend to amend the list soon.
Cheers.
P.S. The Pre EB serials are not totally chronological. The only sure way to date the Bass is to remove the neck. Some prefer not to do this. The serial list should give a general idea.