What is the number of female graduate for all students cohort from Oakwood University in 2013?
female refers to gender = 'F'; graduates refers to grad_cohort; Oakwood University refers to chronname = 'Oakwood University'; in 2013 refers to year = 2013; all sutdents refer to rae = 'X';
SELECT COUNT(*) FROM institution_details AS T1 INNER JOIN institution_grads AS T2 ON T1.unitid = T2.unitid WHERE T2.year = 2013 AND T2.gender = 'F' AND T2.race = 'X' AND T1.chronname = 'Oakwood University'