That's correct!

Today, 1.5 billion people are aged 12–24 worldwide. This number will rise, but not by much more. People are likely to have fewer children in the future, and in coming decades fertility rates will decline. So we're experiencing a "peak" in the number of young people across the world today—and most of them (1.3 billion, in fact) are in poor countries. In rich countries, middle-aged people outnumber youth.