African most populated places/lowest income/poorest places

On this map I used three different layers. On one of them you can see the most populated places of west Africa, on another one you can see the places of Africa with the lowest income per day and the highlighted places on the first layer are the same in the second one because the places with the most population tend to have lower incomes per day. The third layer is also related to the two others in a way that the places that were highlighted in previous layers are again the ones shown on the third layer showing the poorest countries worldwide.