Average annual 20th century population growth peaked in 1987 at approximately 92.3 million people, but the average annual 20th century growth rate peaked in 1967 at 2.11 percent of the previous year's population. Population growth is generally expressed as a percentage, and any precise numerical figure is merely an estimate.
The World Bank and the U.S. Census estimate that the world's population is approximately 7.3 billion individuals, as of 2015. In the last 25 years of the 20th century, between 75 and 92 million people were added per annum to the world population, according to data from the U.N. Department of Economic and Social Affairs. World population growth is a function of global birth rates and death rates and is compiled by synthesizing average national growth rates.