Question: What is the percentage of the object samples in the class of "man" in image no.1?
SQL: SELECT CAST(COUNT(CASE WHEN T1.OBJ_CLASS = 'man' THEN 1 ELSE NULL END) AS REAL) * 100 / COUNT(T1.OBJ_CLASS_ID) FROM OBJ_CLASSES AS T1 INNER JOIN IMG_OBJ AS T2 ON T1.OBJ_CLASS_ID = T2.OBJ_CLASS_ID WHERE T2.IMG_ID = 1