Populations for various african empires and kingdoms

Aug 2018
Someone else might have more information than I on the matter, but I'll contribute what I know.

A quick google search reveals that the Asante Empire(259,000 km2) in what is now Ghana had an estimated 3 Million people in 1874, while the Bornu Empire(129,449 km2) was estimated at approximately 5 Million people in 1892.