The world's population is estimated at 5.3 billion and will increase by 60 percent to 8.5 billion by the year 2025, according to the latest United Nations data published Wednesday.
During 1990 alone, the total is projected to rise by 92 million.
In its biennial fine-tuning of demographic statistics, the U.N. Population Division said the world population was growing at around 1.7 percent a year but by the period 2020-2025 the annual average rate might decrease to one percent.
Spotlighting varying growth rates in different parts of the world, it said while the population of more developed regions increased 45 percent between 1950 and 1990, in less developed regions it soared by 143 percent.
Between 1990 and 2025 the population of developed regions is projected to grow an additional 12 percent while the figure for less developed areas is 75 percent.
The current average annual growth rate for the more developed regions is 0.5 percent and 2.1 percent for the less developed regions. These figures are expected to drop by 2020-2025 to 0.2 percent and 1.2 percent, respectively.