The world is made up of thousands of ethnic groups. The single largest ethnic group on the planet by far is Han Chinese, which represents 19.73% of the global population.
Median age by country. A youth bulge is evident for Africa, and to a lesser extent for South and
Southeast Asia and Central America.
According to the 2006 CIA World Factbook, around 27% of the world's population is below 15 years of age.
Before adding mortality rates, the 1990s saw the greatest number of raw births worldwide, especially in the years after 1995, despite the fact that the birth rate was not as high as in the 1960s. In fact, because of the 163 million-per-year raw births after 1995, the time it took to reach the next 109 reached its fastest pace (only twelve years), as world population reached six billion people in 1999, when at the beginning of the decade, the reaching was designated for 2000, by most demographers.
1985–1990 marked the period with the fastest yearly population change in world history. Even though the early 1960s had a greater growth rate than in the mid and late 1980s, the population change hovered around eighty-three million people in the five-year period, with an all-time growth change of nearly eighty-eight million in 1990. The reason is that the world's population was greater in the mid- and late-1980s (around five billion) than in the early 1960s (around three billion), which meant that the growth rate in the 1980s was no factor on the dramatic population change.