The Census Bureau estimates that the American population will decline suddenly after 2075.
hit over 500 million by 2025.
jump to a billion by 2100.
reach about 403 million by 2050.

the conditions that made the byzantine empire vulnerable to attacks by the muslin turks were the sack of constantinople by western crusaders, the conquests of the sultanate of rum, presence of rival kingdoms and finally the set up of fiefdoms at the empire which were owned by the ghazis (turkish warriors).

where is the subject? hahahaha