>average age of the original builders was well below 20 <
This fascinates me, what are your sources for saying this?
FTC
I'll find out. I was given some graphs by the chap who runs Wiltshire Young Archaeologists for fun but there is no book title on the pages.
I've asked my friend who says "Cripes! I can't remember, but it was a book from our local library I'll go look and get you the reference."
Don't say archaeologists don't ever do anything for you ;-)
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