what is the average uncertain ratio of all candidates?
select avg(unsure_rate) from candidate
what are the numbers for each sex?
select t1.sex, avg(t2.unsure_rate) from people as t1 join candidate as t2 on t1.people_id = t2.people_id group by t1.sex
which gender got the higher number?
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