PARAPHRASE
At the end of the Ice Age, around 10,000 years ago, there were around ten million people in the world. By 1990s, the world's population grew by around 80 million people a year. United Nations predict that by the uyear 2050, the world's population will have grown to around 9 billion people-- a huge number to grasp.
-Davison, Rachel. Growth of the World's Population. Global, 2012, p. 89.