NEW DELHI, India — India's latest census numbers are in, and the 17.7 percent growth rate is within demographers' expectations. More to the point, it reflects the lowest population growth of any decade in the past century.

But even with slower growth, the sheer size of India's population remains the largest obstacle in the country's quest to eradicate poverty. The simple fact is that nearly a fifth of the world's people must eke out a living on only around 3 percent of its land mass and access to only 4 percent of its water.

Those are constants that will not change significantly over the coming decades. However, some expect an upside from India's huge population.

India will likely surpass China as the world's most populous country by 2030. Meanwhile, China's working-age population will peak in 2013, while India's continues to grow. That means that as the rest of Asia ages, India's coming youth bulge could add as much as 2 percent a year to the country's gross domestic product over the next 20 years.

The rub? India faces a dramatic shortfall in education and skills training that could well prevent it from capitalizing on the so-called "demographic dividend."

Meanwhile, Indian resources in areas like transportation, water, medical care and space will remain strained by the demand of the growing number of people who need them.