Countries with frequently missing data

When we look at choropleth maps, there's almost always "no data" for some places. The author of The Unmeasured World analysed 100 choropleth maps and created yet another map that shows for which countries that is most often the case. This quiz is based on that map.

Which countries or country-like entities with a population of > 1 million have the lowest rate of available data in choropleth maps?