Ramallahs population drastically decreased in the late 20th century from 24,722 inhabitants in 1987 to 17,851 in 1997. In the Palestinian Central Bureau of Statistics (PCBS) census in 1997, Palestinian refugees accounted for 60.3% of the population, which was 17,851. There were 8,622 males and 9,229 females. People younger than 20 years of age made up 45.9% of the population, while those aged between 20 and 64 were 45.4%, and residents aged over 64 constituted 4.7%.. What age group made up the smallest percentage of the population?