Harvard carried out a study involving a survey polling people across 30 different nations on a variety of different topics. [1] This includes (among various other more detailed categories) peoples' awareness of various world leaders, their self determined attention rate to news involving various leaders, and their general rating of those leaders. It reveals quite a lot of really interesting and surprising results. For instance about 88% of Americans do not know who Modi is, 85% of Saudis do not know who Putin is, but coming out on top is Israel which sports a less than 5% awareness of Modi. A number of the results really reveal how much of a bubble we all live in.
But the reason it's relevant is because it gives some third party measurement of how people within various countries view their country's leaders. As with all big data like this, people can prove anything they want - so I'm going to avoid giving any more specific numbers other than the neutral ones from above. Okay one more fun one, Tanzania just friggin loves everybody!
[1] - https://www.hks.harvard.edu/publications/reflections-survey-...