Don't forget that a lot of cities have open data portals as well, where you might find more granular data.
Most nations have national statistical agency websites with more limited versions frequently available in English.
There are three main questions to ask yourself when you're looking for data:
Who would care about collecting this data?
What would they be using it for (research, administrative, commercial)?
And, is there a reason the data might NOT exist?
The best place to start any data hunt is in the literature; read what others have produced on your topic and where they got their data. This will give you some places to start.