The population of Laos in 2003 was estimated by the United Nations at 5,657,000, which placed it as number 102 in population among the 193 nations of the world. In that year approximately 4% of the population was over 65 years of age, with another 43% of the population under 15 years of age. There were 100 males for every 100 females in the country in 2003. According to the UN, the annual population growth rate for 2000–2005 is 2.29%, with the projected population for the year 2015 at 7,282,000. The population density in 2002 was a sparse 23 per sq km (60 per sq mi), but the population is unevenly spread, with the greatest concentration in the Mekong Valley. More than 70% of the population is rural, living in some 9,000 villages.
It was estimated by the Population Reference Bureau that only 24% of the population lived in urban areas in 2001. The capital city, Vientiane, had a population of 640,000 in that year. Other large towns, all on or near the Mekong and its tributaries, are Savannakhét, Pakxé, Luangphrabang (the former royal capital), Xaignabouri, and Ban Houayxay. According to the United Nations, the urban population growth rate for 2000–2005 was4.9%.