, it is one of the five highest airports in India, and also the first greenfield airport to be constructed in the Northeastern Region of India, the 100th operational airport in India, and the only airport in the state of Sikkim. The airport was inaugurated by India's Prime Minister Narendra Modi on 24 September 2018 and the first commercial flights from the airport began on 4 October 2018 between Pakyong and Kolkata. Demographics According to the Provisional Population Totals 2011 census of India, the population of Gangtok Municipal Corporation has been estimated to be 98,658. Males constituted 53% of the population and females 47%. The Gangtok subdivision of the East Sikkim district had a population of 281,293, Gangtok has an average literacy rate of 82.17%, higher than the national average of 74%: male literacy is 85.33%, and female literacy is 78.68. About 8% of Gangtok's population live in the nine notified slums and squatter settlements, all on Government land. More people live in areas that depict slum-like characteristics but have not been notified as slums yet because they have developed on private land. Of the total urban population of Sikkim, Gangtok Municipal Corporation has a share of 55.5%. Including Gangtok, East District has a share of 88% of the total urban population. The quality of life, the pace of development and availability of basic infrastructure and employment prospects has been the major cause for rapid migration to the city. With this migration, the urban services are under pressure, intensified by the lack of availability of suitable land for infrastructure development. Ethnic Nepalis, who settled in the region during British rule, comprise the majority of Gangtok's residents. Lepchas, native to the land, and Bhutias also constitute a sizeable portion of the populace. Additionally, a large number of Tibetans have immigrated to the town. Immigrant resident communities not native to the region include the Marwaris, Biharis and Bengalis. Hinduism and Buddhism are the most significant religions in Gangtok. Gangtok also has a sizeable Christian population and a small Muslim minority. The North East Presbyterian Church, Roman Catholic Church and Anjuman Mosque in Gangtok are places of worship for the religious minorities. The town has not been communalised, having never witnessed any sort of inter-religious strife in its history. Nepali is the most widely spoken language in Sikkim as well as Gangtok. English and Hindi being the official language of Sikkim and India