I was in Guangzhou in 1982 as a tourist up from HK. I recall...

I was in Guangzhou in 1982 as a tourist up from HK. I recall visiting a commune, a farming community with its own medical 'hospital' and lone policeman.

And I have distinct memories of having eaten at a restaurant in the city that divided each floor by class system.

Ground level: tables only, no chairs, no table cloths. Rats running around.
First floor: tables & chairs with table coverings. very basic.
Second floor: what we would today consider a standard restaurant livery
Third floor: the most majestic of restaurants I've ever visited.

Back then the population of Guangzhou was 2M. It was a burgeoning fishing village. 40 years later and it has grown to 15M.

If you include Shenzen in that area (a wider metropolis) it's 15M + 13M. A Chinese Mega-city.