Nigeria ranked eighth country in the world living with highest number of slaves
The survey by Walk Free Foundation, the Australia-based human rights group, increased the estimated number of people in modern slavery to 45.8 million from 35.8 million in 2014.
Reuters outlined some key figures from the index below
* India is the country with the greatest number of people living in some form of modern slavery, estimated at 18.3 million
* China came second with an estimated 3.4 million slaves and Pakistan third with an estimated 2.1 million slaves
* Rounding out the top 10 were Bangladesh, Uzbekistan, North Korea, Russia, Nigeria, Democratic Republic of the Congo and Indonesia
* North Korea is the country with the highest estimated proportion of modern slavery with nearly one in every 20 North Koreans, or 4.37 percent of a 25 million population, living in slavery.
* Governments taking the most steps to combat modern slavery were the Netherlands, the United States, Britain, Sweden, Australia, Portugal, Croatia, Spain, Belgium and Norway
* The least action was being taken by the governments of North Korea, Iran, Eritrea, Equatorial Guinea, Hong Kong, Central African Republic, Papua New Guinea, Guinea, the Democratic Republic of the Congo, and South Sudan.