Increasing civilization levels is possible in many Ageod games.
I know that there are 4 levels of civilization: Wild, Cleared, Developed, and Rich. I understand that raising the civilization level increases an area's troop frontage, income, supply production and decreases travel time.
But by how much? Is there a standard increase/decrease across the board for all games? Or do the changes vary title by title?
I believe "Rich" starts at 80 and Wild obviously starts at 0. But where do the 2 other levels start?
Is regional development, beyond raising a few "Developed" areas to "Rich," worth it?