CREATE TABLE candidate (candidate_id NUMBER, people_id NUMBER, poll_source CLOB, date CLOB, support_rate NUMBER, consider_rate NUMBER, oppose_rate NUMBER, unsure_rate NUMBER)
CREATE TABLE people (people_id NUMBER, sex CLOB, name CLOB, date_of_birth CLOB, height NUMBER, weight NUMBER)

which gender got the highest average uncertain ratio.
SELECT t1.sex FROM people AS t1 JOIN candidate AS t2 ON t1.people_id = t2.people_id GROUP BY t1.sex ORDER BY AVG(t2.unsure_rate) DESC LIMIT 1
SELECT "t1"."sex" FROM "people" "t1" JOIN "candidate" "t2" ON "t1"."people_id" = "t2"."people_id" GROUP BY "t1"."sex" ORDER BY AVG("t2"."unsure_rate") DESC FETCH FIRST 1 ROWS ONLY