According to an official statement, the share of Hindus in the population has slipped below 80 per cent for the first time. The population in 2011 was at 121 crores - Hindus make up 79.8 per cent of the population at 96.63 crores.

Muslims, with 17.22 crore people, are 14.2 per cent of the population.

The proportion of Muslims in the population increased by 0.8 per cent between 2001 and 2011. The rate of increase has reduced from the previous decade, when the Muslim share in the population had increased by 1.73 per cent.

Muslims are the only community to register a growth in their share of the population. The growth rate of Muslims is the highest at 24.6 per cent, the census reveals. Hindus follow with a 16.8 per cent growth rate; Christians come next with 15.5 per cent. The growth rates of Sikhs, Buddhists and Jains are less than 10 per cent.

The government says the proportion of Hindus in the population has declined by 0.7 per cent, the proportion of Sikhs has reduced by 0.2 per cent and that of Buddhists have dipped by 0.1 per cent.

Christians are the third largest community with 2.78 crore people, that is 2.3 per cent of the population. They are followed by Sikhs (2.08 crores), Buddhists (84 lakhs) and Jains (45 lakhs).

The data was compiled and readied by early 2014, but reportedly not released because of the national election.

Its release comes ahead of assembly elections in Bihar later this year and in Assam and West Bengal next year.

Sources say the Congress-led UPA government did not favour releasing the data at the time because it pointed at a significant growth in the Muslim population in districts along the eastern border.