Three weeks after 276 schoolgirls were kidnapped in Borno State in northeastern Nigeria, the militant Islamist group Boko Haram has taken responsibility for their abduction. In a video release Monday, leader Abubakar Shekau announced, "I abducted your girls. I will sell them in the market, by Allah." The girls, who are being kept near the Cameroon border, supposedly will be sold by Boko Haram into the modern-day slave market, which the Global Slavery Index estimates at 29.8 million people. 

Modern slavery includes forced labor, trafficking, and child marriage. The estimate is derived from a review of the public records, surveys, and experts analysis. The map below ranks the countries by prevalence:

The 15 countries with the worst slavery situations are also the most active exporters. India, Gabon and Moldova have relatively equal levels of cross-border trafficking. Benin, Côte d'Ivoire, Gambia, Senegal and Cape Verde, however, traffic more slaves into their countries than they export. 

countries with the most slaves International Business Times/Hanna Sender Photo: Hanna Sender