The scientists projected the population of 8 major world regions from 2025 to 2100 to see how changes in fertility rates would affect future populations. They found that the Earth's population will likely stabilize around 10.2 billion by 2095, lower than previously thought. In the decline scenario, the population would peak at 7.7 billion in 2055 and then gradually decrease to 7.2 billion by 2100. In the growth scenario, the population would reach 14.9 billion by 2100. Most of the world's growth will occur in less developed regions, increasing their share of the total population from 75% to 85% by 2050. The age structure in all regions is expected to become more similar, with a median age of 39 and similar proportions of people under 15 and over 64.