Its population is also quite young with over half the population under 25 years old. A large fraction are foreign nationals. (The CIA Factbook estimated that  foreign nationals living in Saudi Arabia made up about 21% of the population. Other estimates are 30% or 33%) Immigrants make up 38.3% of the total population, according to UN data (2019), mostly coming from the Middle East, Asia, and Africa. As recently as the early 1960s, Saudi Arabia's slave population was estimated at 300,000. Slavery was officially abolished in 1962.