Top 6 most populous nations in 1960 were China, India, USA, Russia, Japan, and Indonesia for a combined population of 1,599,152,741. Sixty years later, the Top 6 are China, India, USA, Indonesia, Pakistan, and Brazil for a combined population of 3,853,217,936. And a recent UN report has projected that India will overtake China as the world's most populous nation in 2023.

Source: World Bank