The Nordic countries of Denmark, Finland, Sweden, Norway and Iceland are the rock stars of anti-corruption. Four of them ranked in the top 10 of least corrupt countries on the latest Corruption Perceptions Index from Transparency International while Iceland ranked in the top 20.

The annual index draws on 13 surveys, public records and expert assessments to rank 180 countries using a scale of 0 to 100, where 0 is highly corrupt and 100 is “very clean.” Transparency International is a nonprofit global organization based in Berlin that fights corruption.