A study newly released by the NGO Walk Free Foundation found that North Korea has more slaves per capita than any other nation in the world, with India boasting the largest absolute number of slaves within its borders.

Walk Free Foundation, which conducted its third Global Slavery Index research with the aid of Gallup, notes that one in every twenty people in North Korea is suffering from some form of slavery. The report notes that researchers found instances of slavery in every country in the world but, proportionately, North Korea, Uzbekistan, Cambodia, India, and Qatar had the highest slave populations.

Slavery in Qatar has triggered international condemnation for the nation’s leaders as reports expose the rampant use of slave labor to build facilities for the 2022 World Cup. FIFA has rejected cries to relocate the World Cup to a nation that respects the rights of workers.

India, the nation with the largest number of slaves worldwide, is home to 18.4 million people subjected to some form of slave labor.

Walk Free Foundation estimates the global slave population to be at nearly 46 million.

The organization noted that the number of slaves it estimated to live in chains worldwide increased exponentially since 2014, the last time the index was published. This is not likely a product of the increased popularity of slavery, however, but a result of greatly improved technology with which to access the far-flung areas of the planet where authorities make it more difficult to fully gauge slave populations. Parts of the study note, however, that unresponsive governments have artificially deflated the nation’s rankings as the group could not prove many allegations of slavery. Cuba, for example, which ranks 35 out of 167 countries on the index, did not allow for the group to conduct much on-the-ground research, preventing the NGO from confirming how many Cuban doctors are currently enslaved by the communist government.

In the case of North Korea, the ever-expanding population of North Korea defectors provide for more interviewees to contribute to the collective knowledge base used for the survey. The most highly-publicized mass defection from North Korea in the past year consisted of a group of slaves — restaurant workers based in China who were forced to send their entire salaries back to Pyongyang and rely on a food stipend to live. Upon defecting to South Korea, the Kim Jong-un government accused Seoul of having “abducted” the restaurant workers and continues to call for their “release” to this day.

In addition to slaves in the tourism industry, reports surfacing last year accused the North Korean government of generating nearly $2 billion in revenue from selling slave labor abroad, particularly to Russia, China, and Mongolia. Former slaves, now defectors speaking out, said they opted to work for nothing in foreign countries because even their meager food rations abroad were better than what the average North Korean citizen could eat at home.

The U.S. State Department has branded North Korea a “Tier 3” country for human trafficking, warning that many citizens are under threat of falling into forced labor in agriculture, mining, or sex slavery.