Table of military units produced
by primitive tribes at various
stages of their expansion:

Unit Type	# of cities
------------------------------
Flint Dagger		1-8
Flint Spear		9-16
Flint Sword		17-25
Bronze Dagger		26-31
Bronze Spear		32-40
Bronze Sword		41-45
Iron Dagger		46-50
Iron Spear		51-56
Iron Sword		57+