Gold from conquering cities

[Fistleaf]

How is the amount calculated?
By population size, number of buildings captured/destroyed, trade routes in the city, or current wealth of the civ?
Wealth of the civ seems to have little impact seems poor civs can give plunder which is several times their current available gold.

[Theben]

B/c you're plundering it from the people, not the treasury.

[Blaupanzer]

You're not taking a bribe, you are robbing homes, churches, and public buildings.

[Fistleaf]

So logically, the gold should come from destroyed buildings. Since all culture-producing buildings are automatically destroyed, I would assume cities with many of such buildings yield the most gold.