If it’s the decrease, yeah, something happened in the mid-late-70’s that made fertility rates go down all over Africa (if not the world). Of course some countries reacted later and some earlier but that’s beyond the point. Isn’t it when everybody was writing about the pending overpopulation ? May be the WHO had prioritized on it back then.

If it’s the increase, yeah it’s not unique either but there are exceptions like Nigeria and Ghana or Tanzania. I don’t know if it’s because their rates were already high or if it’s policy matter (especially in Tanzania) or if it’s because they were at the end of a growth circle of their own.
It is very possible that the 1950 to mid-70’s increase is actually a long cycle of African countries getting back to their pre-colonization or pre-slavery rates.

It’s still interesting.

Regarding the “Gabon bump”….surely the question is whether that bumb was unique to Gabon…It seems common to other economies. RSA, Botswana and other more stable economies exhibit similar trends..so one can only speculate that its “external factors”.