What country do we know this least about Demographically?
Seeing the non-existence of many state-run censuses leaves most demographic data to be estimated by the UN. It is very likely that this data may be wildly over or under shooting the actually population and TFR of many countries especially in Africa or Asia. For example, I imagine that the Republic of Congo (not the DRC) is potentially a closer to 3.5 than the 4.16 estimated by the UN, based on Urbanism and vibes lol. But its a serious question and I wonder how much literature exists about the lack of knowledge we have about populations and what other indicators can be used to assess this.