The population of Laos is 6.3 million people (estimated mid-2009) with an annual growth rate of 2.4%. The population density is about 27 people per sq km. The most densely populated area is Vientiane capital which is around 153 people per sq km and all the other provinces have below 40 people per sq km. Among the least densely populated provinces (less than 10 people per sq km) are Xaysomboun, Sekong, Attapeu and Phongsaly. Savannakhet province has the largest population, but is not the most densely populated because the province is large.