The Australian-based human rights group, the Walk Free Foundation, conducted its annual survey of slavery around the world and discovered that there are 35.8  million people in bondage in 167 countries.

Leading the world in the number of slaves is India with more than 14 million. The highest number of slaves per capita belongs to Mauriitania with 4% of its population of 3.9 million living in slavery.

Qatar, which will host the 2022 soccer World Cup came in 4th on the list. Human rights groups accuse Qatar of using slave labor to work its massive stadium building program to get ready for the games.

Reuters:

The next highest prevalence rates were found in India, Pakistan, Democratic Republic of Congo, Sudan, Syria and Central African Republic.

The index showed that 10 countries alone account for 71 percent of the world's slaves.

After India, China has the most with 3.2 million, then Pakistan (2.1 million), Uzbekistan (1.2 million), Russia (1.05 million), Nigeria (834,200), Democratic Republic of Congo (762,900), Indonesia (714,100), Bangladesh (680,900) and Thailand (475,300).

For the first time, the index rated governments on their response to slavery. It found the Netherlands, followed by Sweden, the United States, Australia, Switzerland, Ireland, Norway, Britain, Georgia and Austria had the strongest response.

At the opposite end of the scale, North Korea, Iran, Syria, Eritrea, Central African Republic, Libya, Equatorial Guinea, Uzbekistan, Republic of Congo and Iraq had the worst responses.

Every country in the world apart from North Korea has laws that criminalise some form of slavery, yet most governments could do more to assist victims and root out slavery from supply chains, Walk Free Foundation's head of global research said.

"What the results show is that a lot is being done on paper but it's not necessarily translating into results," Fiona David told the Thomson Reuters Foundation by telephone from Canberra.

"Most countries got 50 percent or less when we looked at the strength of their victim assistance regime. It's also striking that ... out of 167 countries we could only find three (Australia, Brazil and the United States) where governments have put things in place on supply chains."

The report showed that conflict had a direct impact on the prevalence of slavery, David said, citing the example of the Islamic State militant group which has abducted women and girls in Iraq and Syria for use as sex slaves.

"What our numbers show is the correlation really is quite strong so as an international community, we need to make planning for this kind of problem part of the humanitarian response to crisis situations," David said.

Islamic State has sold thousands of ethnic minority women into slavery, mostly to become "wives" to their fighters. Boko Harum in Nigeria has done the same thing. This appears to be financially motivated, not religiously inspired, although the terrorists probably get some satisfaction from selling non-believers.

As for the rest of the world, it appears that preventing slavery is not high on the agenda of most governments. In some countries, the government almost certainly looks the other way. Until every country takes the problem seriously, millions of people will suffer for their indifference.