tallest building at 161 metres. Demographics Population A resident of Chennai is called a Chennaite. According to 2011 census, the city had a population of 4,646,732, within an area of 174 square kilometres administered by the Municipal Corporation, working out a population density of 26,705 persons per square kilometre; that had 11 lakh households, with 51% of them living in rented houses. The city's limits were expanded later in 2011 to 426 square kilometres and its population reached 7,088,000, resulting in a population density of 16,639 persons per square kilometre, with Chennai Municipal Corporation being renamed as Greater Chennai Corporation. As of 2019, 712,000 families live below poverty line, which is about 40 percent of the 1.788 million families in the city. Languages Tamils form the majority of Chennai's population. English is spoken largely by white-collar workers, often mixed into Tamil. In 2001, out of the 2,937,000 migrants (33.8% of its population) in the city, 61.5% were from other parts of the state, 33.8% were from rest of India and 3.7% were from outside the country. As per the 2001 census, the number of speakers mother tongue wise are as follows, Tamil is spoken by 3,424,107 (78.8%), followed by Telugu by 419,209 (9.7%), Urdu by 180,245 (4.1%), Malayalam by 113,828 (2.6%), Hindi by 104,084 (2.4%), and Kannada by 22,250 (0.5%). Korean, Japanese, French, Mandarin Chinese, Russian, German and Spanish are some of the languages spoken by the 250,000 foreign expatriates residing in the city. Religion and ethnicity Chennai, along with Bengaluru, Mumbai and Delhi, is one of the few Indian cities that are home to a diverse population of ethno-religious communities. Minorities include Telugus, Marwaris, Gujaratis, Parsis, Sindhis, Odias, Goans, Kannadigas, Anglo-Indians, Bengalis, Punjabi, and Malayalees. As per the religious census of 2011, Chennai's population was 80.73% Hindu, 9.45% Muslim, 7.72% Christian, 1.11% Jain, 0.06% Sikh, 0.06% Buddhist, <0.04% followed other religions and 0.83% followed no religion or did not indicate any religious preference. Housing In a 2013 survey titled 'Emerging trends in real estate in Asia Pacific 2014', Chennai emerged in the top 25 real estate destinations list in the Asia Pacific region. The city ranked 22nd in the list. There are about 1,240 slums in Chennai home to about 900,000 people. Per 2011 census, there are 1.1 million households in the city and the residential housing stock available is 1,150,000 – a surplus of about 50,000 houses. About