It’s not a simple function of time and population. Fertility rate varies by country and more specifically by economic achievement. Population isn’t evenly distr

It’s not a simple function of time and population. Fertility rate varies by country and more specifically by economic achievement. Population isn’t evenly distributed in either of those categories. We saw rapid gains due to China and then India modernizing. Now they are declining and peaked and its Africa’s turn but Africa is a continent made up of many countries in various states of development or regression which makes it very difficult to predict. If we take the happy path and all goes well with each country continuing to improve then they will peak quickly having the advantages of modern technology and three advanced economies investing in them.