(1/8/04 4:59 pm)
What you want to know is impossible to determine thanks to that little word "oral." There are no records so all we have is speculation. We have had similar discussions before and here is a link to one of the better and more recent ones in the archives:
Also, Graham Anderson has written an interesting book about which myths may have influenced our modern fairy tales. It's titled Fairytale in the Ancient World. Here is a link to it on Amazon.com:
I have included the histories to the 27 tales on Amazon. They don't include Anderson's theories (yet) but trace the literary history of the tales, including some of the speculation about their age in oral folklore. Each tale is different, so even grouping them into one lump to ask "how old are fairy tales" is impossible.