This is a graph of doctors per capita, right? It's a bar chart, right?
This will workout how many doctors there are per person. For example, if there are 50 doctors in a country with 500 people, there are 10 people per doctor. If there are 50 doctors in a country in a country with 5000 people, then there are 100 people per doctor. Using measures like this is one of the ways demographists, anothrpologists and economics etc. work out how developed a country is.