You’re welcome. That was so fast, I missed the “meep, meep!” ;’)
from Acme, Inc!
Why the year 320? The city may have been at a population peak, but all of its major architecture was already 200 years old, except for Caracella’s Baths, which were 100 years old. Of course within a few years, as first Constantinople was established, and then the western capital moved to northern Italy, Rome went into a rapid decline, which was accelerated by the sacking of the city first by the Visigoths, then by the Vandals.