CREATE TABLE table_1414743_1 (students INT, pupil_teacher_ratio VARCHAR)

What is the highest number of students with a teacher:student ratio of 20.8?
SELECT MAX(students) FROM table_1414743_1 WHERE pupil_teacher_ratio = "20.8"
SELECT MAX("students") FROM "table_1414743_1" WHERE "20.8" = "pupil_teacher_ratio"