A look at how one half of the country prepares for the challenge of educating its growing young workforce and the other on how to support the elderly.

2.1 is a magic number, one that for years looked unimaginable for India. The average number of children any given woman in a country's population is expected to have during her lifetime is known as the Total Fertility Rate (TFR). Demographers are in agreement that as TFR of 2.1 is the "replacement level", i.e. the number of kids women in a population need to have so that the population will just maintain itself, neither grow nor shrink (the 0.1 takes care of the likelihood of unnatural deaths).

Year by which projected TFR will be 2.1

In 1960, India's TFR was 6, and our population ever declining must have seemed too far off to imagine. As of 2010, India's TFR according to the UN is 2.5, and many states have already reached replacement levels. If there was ever a chart that showed how we are almost a nation of many nations, it is this one: Kerala hit 2.1 in 1998 and is now already down to European levels of low fertility, while Uttar Pradesh will reach this milestone a full 30 years later, in 2027. So as one half of the country prepares for the challenge of educating and training its growing young workforce, the other must increasingly think of pensions and how to support the elderly.

(Note: the data comes from the office of the Registrar General in India. Data for north-eastern states (excluding Assam) was grouped together by the original source.)