This is only because:
A. Hispanics count as their own race instead of Spanish speaking whites
B. Half-white half Asian/black/Hispanic/Native American children all count as the non-white ethnicity. If even half of them counted as white instead of minority, the “white” percentage would be 3.5% higher (7% of children are interracial, most half white, half something else).
Most of my family tree is good European stock. But, alas, I do have some French in me.