Afghanistan, North Korea and Somalia were at the other end of the scale. They tied with a score of 8 on a 100-point scale while Denmark and New Zealand were given scores of 91.
The Corruption Perceptions Index, which ranked 177 countries, is based on expert opinion about each country's institutions. Huguette Labelle, the Transparency International chairwoman, said that public accountability is a major factor in preventing corruption.
"The top performers clearly reveal how transparency supports accountability and can stop corruption," said Labelle. "Still, the better performers face issues like state capture, campaign finance and the oversight of big public contracts which remain major corruption risks."