Figure 1 shows significant falls in TFR in all regions of the world, although the poorest part of the world (Sub Saharan Africa) still maintains a high but declining level of fertility.
Some Muslim nations’ birthrates may be in decline, but in many places their fertility rate is far higher than the rest of the population. This applies here as well in Sub Saharan Africa. Approximately 50% of the population of Sub Saharan Africa is currently made up of Muslims. This percentage has been growing significantly not declining just as it is in the USA and Europe.
Islam is the world’s fastest growing religion. This is due mostly to their high fertility rate.
“the number of Muslims is expected to increase by 70% from 1.8 billion in 2015 to nearly 3 billion in 2060.”