In Pictures: The 25 Most Corrupt Countries in the World

Every year, Berlin-based non-profit Transparency International publishes its "Corruption Perceptions Index," a list of 180 countries and territories ranked "by their perceived levels of public sector corruption."

The organization has chapters in more than 100 countries – "From villages in rural India to the corridors of power in Brussels" – and a clear, ambitious mission statement: "We want a world free of corruption."

By its own admission, the goal is some way off, despite the continued work of volunteers, NGOs, activists and reporters across the world. Introducing 2017's list of countries and their perceived levels of corruption, the organization said: "This year's Corruption Perceptions Index highlights that the majority of countries are making little or no progress in ending corruption, while further analysis shows journalists and activists in corrupt countries risking their lives every day in an effort to speak out."

The analysts produce the Corruption Perceptions Index based on input from 13 data sources, all of which must meet a number of specific criteria to be included. As the organization states, measuring corruption can only ever be a matter of perception as it "generally comprises illegal activities, which are deliberately hidden and only come to light through scandals, investigations or prosecutions."

It continues: "While researchers from academia, civil society and governments have made advances in terms of objectively measuring corruption in specific sectors, to date there is no indicator which measures objective national levels of corruption directly and exhaustively determined as a perception."

The most recent list, published in February 2018 and drawing on the previous two years' analysis, finds New Zealand and Denmark at its most squeaky clean end, ranking 89 and 88 respectively (where 100 represents the least corrupt country and zero the most corrupt). The U.S. was perceived as the 16th least corrupt country in the world, though the data was collated before many of the alleged scandals that have dominated the news agenga in the U.S. over the past two years.

At the most corrupt end of the scale, where Newsweek's slideshow begins, we find many countries long tainted by civil war, poverty and historical corruption. Two thirds of the countries included in the study received a score of below 50. Here are the very worst of them all.