Tirupati, with a population of 288,000 and a literacy rate of over 85 percent, is the 9th most populous city of Andhra Pradesh, falling under the Chitoor district. The Tirumala Venkateswara Temple located in Tirupati is one of the most important Hindu Pilgrimage sites in India. Telugu is the official language of the city. As per the 2011 census, the total population of the district is 4.1 million and the literacy rate is over 71 percent. 46 percent of the districts population is part of the workforce. This includes 61 percent working in the agriculture sector, 3 percent in the household industry and 36 percent working in services and industry. The entire economy of the city is directly or indirectly dependant on the Tirumala Tirupati Devasthanams(TTD) that is headquartered at Tirupati. Established in 1932, TTD is an independent Trust which manages the main Tirumala Venkateswara Temple and the temples in Tirupati and is also involved in several social activities. Being a major religious destination, Tourism and Hospitality are the main industries in Tirupati. Upper Tirupati or Tirumala has been an established centre of Vaishnavism since the 5th century A.D., and was praised by Alvars. The temple rites were formalized by the Vaishnavite saint Ramanujacharya in the 11th century AD. It is believed that the main deity of the Shri Ranganathaswamy Temple of Srirangam, located in Tiruchirapalli in Tamil Nadu was brought to Tirupati during the Muslim invasions of the 1300s. The city grew as a spiritual hub under the rule of the Cholas, Pallavas and the Vijaynagar Kingdom. There was no human settlement at Lower Tirupati until the year 1500. With the growing importance of Upper Tirupati, a village was formed at the present site and was named "kotturu".