Explanation:

A systematic and modern population census, in its present form was conducted non synchronously between 1865 and 1872 in different parts of the country. This effort culminating in 1872 has been popularly labeled as the first population census of India However, the first synchronous census in India was held in 1881. Since then, censuses have been undertaken uninterruptedly once every ten year.
Think
•In which census the population decreased from the previous census?