The year 1921 is often referred to as the “Year of the Great Divide,” the last period in which India’s population declined, due to the effects of famine and spanish flu epidemic. In fact, the 1921 Census remains the only one ever to record a net reduction in the rural population.⁣

India lost between 16-21 million lives to that between 1918-21. The 1918 influenza epidemic spread in two phases: in the first, less virulent phase (June 1918 onwards), urban areas were affected; in the second, more virulent phase (September 1918 onwards), rural areas were severely affected.⁣

The report on the Census of India, 1921 – the fifth general census – was prepared by J.T. Marten, the then census commissioner of India. Marten had also prepared the census reports for the Central Provinces and Berar in 1911.⁣

The 1921 Census observes that the sex ratio across India fell in the previous two decades. The birth statistics, the census says, suggest that the proportion of girls born to that of boys born declined during this period. ⁣

It also says that in the five years before 1921, the decline in the proportion of women was because of the high number of deaths due to plague and influenza among women and “the absence of famine mortality which selects adversely to males” (that is, relatively lower number of deaths among men than women during famines). ⁣

It also found that the sex ratio was higher in the south and east, and lower in the north and west – a trend seen in previous censuses too.⁣

In 1921 census, the category of depressed classes was used for the first time.⁣

During the next three decades (1921 -51), the rate of population growth continued at a level of over 1% per annum.⁣