Thanks for pointing that out. Our World In Data’s data is out of date [1], I keep poking them to update their fertility rate data but get no response (maybe busy with COVID data sets, I have no context into why).
I suspect that Covid is going to run a coach and horses right through that improvement. The best ways of getting population growth down in places like Africa are education and a strong, stable economy - and it's just trashed both.
[1] https://ourworldindata.org/fertility-rate