BEIJING -- The population of Beijing fell 0.1 percent to 21.7 million at the end of 2017 from a year ago, authorities said Friday.

Of the capital's residents, 18.77 million lived in urban areas, accounting for 86.5 percent of the total population.

About 2.26 million people were under 14 years old, about 10.4 percent of the whole population, while 3.58 million people were 60 years old or above, accounting for 16.5 percent, according to Pang Jiangqian, deputy head of Beijing municipal bureau of statistics, at a press conference.

Beijing plans to cap its population at 23 million by 2020 to address "big city problems," such as traffic congestion and pollution.

To meet the goal, Beijing has taken measures to move non-capital functions away from the city, such as relocating wholesale markets and closing polluting factories.