North Korea remains at the top of the index of countries where slavery is worst. The index was drawn up by experts from the British company Veriswalk Mediastock and includes 198 countries, the BNR said. The European Union is the region where the so-called modern slavery increased most this year. The reason is the influx of more than 100,000 migrants. Romania, Greece, Italy, Cyprus and Bulgaria are the EU countries where slave labor is most used. 21 million people in the world, including children, are forced to work, according to data from the International Labor Organization. The situation has worsened most in Turkey. India has the greatest improvement. Thailand has also made significant progress, although the risk remains high in both countries.