10 most populous countries chart by population

The Han Chinese are the world's largest single ethnic group, constituting over 19% of the global population in 2011. The world's most-spoken first languages are Mandarin Chinese (spoken by 12.44% of the world's population), Spanish (4.85%), English (4.83%), Arabic (3.25%) and Hindustani (2.68%).[81] The world's largest religion is Christianity, whose adherents account for 33.35% of the global population; Islam is the second-largest religion, accounting for 22.43%, and Hinduism the third, accounting for 13.78%.[81] In 2005, around 16% of the global population were reported to be non-religious.[91]

Reference 1: Population and Approx.% of world population.

Reference 2: China[note 4], India, United States, Indonesia, Brazil, Pakistan, Nigeria, Bangladesh, Russia and Mexico.

Source: http://en.wikipedia.org/wiki/World_population