So you are deriving a conclusion based on the limited information you have. I fail to understand how drawing a conclusion to anything can compare to actually being there.
If my grandfather ever heard someone my age say they know exactly what it felt like to be a soldier on the front lines in WWII, just because they have the complete set of Time Life Books, he'd probably slap them silly. Even if they said "I can INFER what WWII was like on the front lines." Conclude all you want, it is nothing compared to actually being there.
A bowl of cereal lies spilled on the kitchen floor. A cat is lapping up the puddle of milk. On the edge of the table are a few scattered doggie treats and spilled milk. Across the floor, a trail of crumbs lead to a large dog with his muzzle in a box of doggie treats. A toddler stands nearby gnawing on a doggie treat and giggling. Only the dog and toddler have milk splashed up their legs, but the cat has doggie treat crumbs on one paw. When you walk into the room, the toddler screams in excitment "COOKIE!"
What happened and who spilled the cereal? There is only one correct answer.
What does the projecting the population have to do with anything? Obviously you are missing my arguments by a mile, and using trivial data as a prop to build your case. In the event the peoples of 1313 actually cared about population calculations and it affected their day-to-day life, then it becomes an acceptable entry.
I don't want documentation, I want to know and feel first hand. Only then we can truly understand.