AMMAN, Jordan (AP) — The United Nations population agency says the world's population grew to 7.4 billion in 2016, with a substantial youth bulge challenging political and social systems across the planet.

The United Nations Population Fund released its 2016 State of the World Population report Thursday in Amman, Jordan. The report highlights the potential fallout — and gains — to be had by overcoming the world's clear gender inequality in the half of the world's population under the age of 24.

The report focuses on the well-being of 10-year-old girls as indicators of development success or failure. It says 89 percent of the world's 125 million 10-year-olds live in developing countries where girls face obstacles to equal education, healthcare and safety.