Modding Victory Conditions

[Starrynite120]

I'm looking at Modding the victory conditions through adding prerequisites to the victory wonders in the XML (I know where the correct XML file is). I want to make it so you cannot construct the mind flower unless you have a city with 30 population (since harmony is about growth), and you need 20 virtues before you can construct the Exodus gate. Problem is, I don't know what that would represent in the code, meaning I'm not sure how to refer to how many virtues you have and what population a city has. Could anyone tell me what that name would be? Would it be something like LocalPop for population, or something like AdoptedVirtues?