The approximate distribution of blood types in the U.S. population is as follows:
- O-positive: 38 percent.
- O-negative: 7 percent.
- A-positive: 34 percent.
- A-negative: 6 percent.
- B-positive: 9 percent.
- B-negative: 2 percent.
- AB-positive: 3 percent.
- AB-negative: 1 percent.