I can't believe I am going to say this. But what about Western countries like Mexico and Brazil. They have about 2/3rd our population but have a higher grouwth rate.
Or are you only considering Europe and the USA as Western countries?
Mexico and Brazil are Western countries, of course.
And they are in the same boat.
Brazil has a reproductive growth rate of 1.04%.
Mexico has an rpr of 1.16%.
The USA has an rpr of .91%.
They are barely growing.