Database: thrombosis_prediction
Question: For all patients who are older than 55 years old, what is the percentage of female who has abnormal prothrombin time (PT)?
SQL: SELECT CAST(SUM(CASE WHEN T2.PT >= 14 AND T1.SEX = 'F' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(*) FROM Patient AS T1 INNER JOIN Laboratory AS T2 ON T1.ID = T2.ID WHERE STRFTIME('%Y', CURRENT_TIMESTAMP) - STRFTIME('%Y', T1.Birthday) > 55