I recently learned that 3.14% of our military was African American during Vietnam - and thought the number seemed quite low.
EDIT: thank you u/KNHaw for kindly showing me the correct percentage (12.6%). Sorry for the misinfo!
It does seem unusually low. Where did you get that statistic? This site claims (my emphasis):
The Vietnam War saw the highest proportion of blacks ever to serve in an American war. During the height of the U.S. involvement, 1965-69, blacks, who formed 11 percent of the American population, made up 12.6 percent of the soldiers in Vietnam... the percentage of black combat fatalities in that period was a staggering 14.9 percent.
Source: The Oxford Companion to American Military History. 1999.