The Walk Free Foundation released its first Global Slavery Index, ranking 162 countries on the number of people in slavery and bondage per capita and the absolute number of slaves. It said the number of victims of modern slavery globally is between 28.3 million and 31.3 million.
Two relatively small and very poor countries, Mauritania in Africa and Haiti in the Caribbean have the most slaves per capita, followed by Pakistan. Mauritania and Haiti both have high rates of child marriage and of human trafficking, the group said.
Pakistan also ranks third in total number, following the world's two most populous countries, India and China. Almost half the world's slaves, 14 million, are in India, the group said, with 2.9 million in China and 2.1 million in Pakistan.
"The India country study suggests that while this involves the exploitation of some foreign nationals, by far the largest proportion of this problem is the exploitation of Indians citizens within India itself, particularly through debt bondage and bonded labor," the report said..
Britain, Iceland and Ireland are at the other end of the list. But Walk Free said none of the three are entirely free of slavery, with an estimated 100 in Iceland, which has a total population of about 300,000.
The group estimated the number of slaves in Britain at 4,200 to 4,600.
"An analysis of the U.K. response on this issue confirms much more can be done, as the government response is fragmented and disjointed, and that there have been alarming systemic failures, including the loss of trafficked children from care," the Walk Free report said.