Mexico

Mexico ranks 10th with 131 million people, making it 15 million fewer than Russia's #9 and the second-largest population in the Americas. Its growth rate has halved from 2.6% annually in the 1970s to about 1.2% today, as urbanization and family planning reshape demographics. This slowdown is faster than the global average decline of 0.3 percentage points per decade. Over 80% of Mexicans now live in urban areas, a shift that has cut fertility to 1.8 children per woman—below the replacement rate.