Kerala is home to 2.8% of India's population; with a density of 859 persons per km2, its land is nearly three times as densely settled as the national average of 370 persons per km2.[45] As of 2011[update], Thiruvananthapuram is the most populous city in Kerala.[46] In the state, the rate of population growth is India's lowest, and the decadal growth of 4.9% in 2011 is less than one third of the all-India average of 17.6%.[45] Kerala's population more than doubled between 1951 and 1991 by adding 15.6 million people to reach 29.1 million residents in 1991; the population stood at 33.3 million by 2011.[45] Kerala's coastal regions are the most densely settled with population of 2022 persons per km2, 2.5 times the overall population density of the state, 859 persons per km2, leaving the eastern hills and mountains comparatively sparsely populated.[47] Kerala is the second-most urbanised major state in the country with 47.7% urban population according to the 2011 Census of India.[48] Around 31.8 million Keralites are predominantly Malayali.[45] The state's 321,000 indigenous tribal Adivasis, 1.1% of the population, are concentrated in the east.[49]: 10–12