Rh factor:
In addition to the ABO blood grouping system, the other prominent blood grouping system is the Rh grouping.
About 80% of the human population have the Rh antigen on the surface of their red blood cells, which is also known as the Rh factor.
This decides whether the blood group is positive or negative.
If the Rh factor is present, an individual is rhesus positive (Rh+ve); if the Rh factor is absent, the individual is rhesus negative (Rh-ve).
Final answer: 80%