First of all, a huge thanks to user Dekkie for letting me use her map as a base!
Now, for the extensive caveats:
• There were not enough sources listing population data for cities like Athens, Madrid, Moscow, Vienna, Augsburg...etc which is why they weren't on the quiz.
• Censuses were not really a thing back then, therefore population figures used for the quiz are rough estimates and might not be accurate.
• One of the cities, Bolghar, which was grey-boxed, is not shown on the map.
Now, for the extensive caveats:
• There were not enough sources listing population data for cities like Athens, Madrid, Moscow, Vienna, Augsburg...etc which is why they weren't on the quiz.
• Censuses were not really a thing back then, therefore population figures used for the quiz are rough estimates and might not be accurate.
• One of the cities, Bolghar, which was grey-boxed, is not shown on the map.