Yemen's population is  million by  estimates, with 46% of the population being under 15 years old and 2.7% above 65 years. In 1950, it was 4.3 million. By 2050, the population is estimated to increase to about 60 million. Yemen has a high total fertility rate, at 4.45 children per woman. It is the 30th highest in the world. Sana'a's population has increased rapidly, from roughly 55,000 in 1978 to nearly 2 million in the early 21st century.