Transparency International has a yearly corruption perceptions index. The graph here is for 2019 (high score – lighter colors – clean, low score – darker colors – corrupt).
The Corruption Perceptions Index ranks 180 countries and territories by their perceived levels of public sector corruption, according to experts and business people. This year’s analysis shows corruption is more pervasive in countries where big money can flow freely into electoral campaigns and where governments listen only to the voices of wealthy or well-connected individuals.
At the bottom of the page is a link to download an extensive data set including a timeseries from 2012 – 2019. Each country has a designated region and so one could compare corruptions by region in a stats course.