The Corruption Perceptions Index (CPI) just released for 2012 by Transparency International ranks 176 nations according to the perceived corruption levels of their public institutions. The CPI uses a scale of 0-100, 0 being the most corrupt and 100 the least corrupt. For 2012 the most corrupt countries, ranking at the bottom with a score of 8, are Somalia, North Korea and Afghanistan. At the other end of the spectrum, ranking at the top with a score of 90 are Denmark, Finland and New Zealand.
The CPI is a composite index based on a combination of surveys and assessments of corruption compiled by different reputable institutions worldwide.
See complete report: Transparency International – 2012 Corruption Perceptions Index