Russia
The United States has often ranked as the nation that incarcerates the highest percentage of its population. As of the most recent statistics (2017), the tiny island nation of Seychelles off the coast of East Africa. Out of 100,000 members of the national population, Seychelles has 799 imprisoned. The United States is close behind that rate, and first of all developed nations, with 666 incarcerated out of every 100,000 inhabitants. Russia stands at 428, with other developing countries dotting the list between the USA and Russia -- for instance, El Salvador at 586, Turkmenistan at 583, Cuba at 510.