There are four different types of blood: A, B, O and AB. Each of these can either be positive or negative, depending on whether a protein known as the "Rh factor" is present in the red blood cells. Each blood type has slightly different qualities. For instance, those with type O- are universal donors. This means they can give blood to anyone. AB+ on the other hand is a universal acceptor, so they can receive donations from anyone. Only around seven percent of the world are Rh negative.

As Statista's Anna Fleck shows in the following map, the most common blood group worldwide is O positive.

Europe tells a slightly different story, however, with the majority of its countries' populations having A positive blood. Only two countries in the World Population Review's records have a greater share of B positive blood types: Pakistan and Bangladesh.