Not all ethnic groups have the same mix of these blood types. Hispanic people, for example, have a relatively high number of O's, while Asian people have a relatively high number of B's.
The mix of the different blood types in the U.S. population is:
1* - Caucasian | 2* - African- American | 3* - Latino- American | 4* - Asian
| 1* | 2* | 3* | 4* | |
| O + | 37% | 47% | 53% | 39% |
| O - | 8% | 4% | 4% | 1% |
| A + | 33% | 24% | 29% | 27% |
| A - | 7% | 2% | 2% | 0.5% |
| B + | 9% | 18% | 9% | 25% |
| B - | 2% | 1% | 1% | 0.4% |
| AB + | 3% | 4% | 2% | 7% |
| AB - | 1% | 0.3% | 0.2% | 0.1% |
Some patients require a closer blood match than that provided by the ABO positive/negative blood typing.
Reference(s).. www.redcrossblood.org