According to the first economic census, conducted in 1977, 99.7% of the villages in Kerala had a primary school within 2 kilometres (1.2 mi), 98.6% had a middle school within 2 kilometres (1.2 mi) and 96.7% had a high school or higher secondary school within 5 kilometres (3.1 mi).[9]: 62 In 1991, Kerala became the first state in India to be recognised as completely literate, although the effective literacy rate at that time was only 90%.[10] In 2006–2007, the state topped the Education Development Index (EDI) of the 21 major states in India.[11] As of 2007[update], enrolment in elementary education was almost 100%; and, unlike other states in India, educational opportunity was almost equally distributed among sexes, social groups, and regions.[12] According to the 2011 census, Kerala has a 93.9% literacy, compared to the national literacy rate of 74.0%.[13] In January 2016, Kerala became the first Indian state to achieve 100% primary education through its Athulyam literacy programme.[14]