Transparency International has developed the Corruption Perceptions Index. It is an annual ranking that measures the perceived levels of public sector corruption in countries worldwide.

Korea's CPI is 4.2, On a scale of 1-10 with 10 being a clean government and 0 being corrupt

There is no country that is completely free of corruption. Transparency International's Corruption Perceptions Index ranks countries based on perceived levels of public sector corruption. Denmark, New Zealand, Finland, Sweden, and Switzerland are often ranked among the least corrupt countries in the world.

Oman is seen as one of the least corrupt countries in the Middle East. Transparency International's Corruption Perceptions Index ranks Oman fairly well in terms of corruption levels compared to other countries in the region. However, like any country, there are still instances of corruption that may occur.

Chad is the most corrupted country in the world according to 'forbes'

According to the global corruption perceptions index It's Somalia, but I'd put my money on North Korea.