CREATE TABLE candidate (people_id VARCHAR(255), unsure_rate INTEGER); CREATE TABLE people (sex VARCHAR(255), people_id VARCHAR(255))
which gender got the highest average uncertain ratio.
    
SQL: 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