I've just come across this article:
en.wikipedia.org/wiki/History_of_breastfeeding#cite_note-29
& the table near the bottom shows the uptake of exclusive breastfeeding around the world. Some of the figures are a bit out of date but I think it gives a reasonable picture.
Some of the lowest figures come from some of the least developed countries & the UK actually comes out quite well.
Am I being naive to think that women in countries like Niger wouldn't have great access to formula (I know a bit about the Nestle controversy but probably not enough)? And if not, what are they giving the babies?