Those two Dallas public schools should not rank there, however, they are in because the divisity of student is same as population. It is funny to see total enrollment is only 200 to 300 students because it is difficult to find top students to fit such divisity.

Top 1 and Top 2 public school national wide is
T.J. High School for S.T. at North Virgina
(SAT is # 1 among all public and private high school), 2700 students, 30% Asian.
Stuyvesant High School, N.Y.
2000 students, 67% Asian.

Both are not ranked in this list because they are magnet school.