
10. Find the Ratio of male and female athletes participated in all olympic games.
    with t1 as
        	(select sex, count(1) as cnt
        	from olympics_history
        	group by sex),
        t2 as
        	(select *, row_number() over(order by cnt) as rn
        	 from t1),
        min_cnt as
        	(select cnt from t2	where rn = 1),
        max_cnt as
        	(select cnt from t2	where rn = 2)
    select concat('1 : ', round(max_cnt.cnt::decimal/min_cnt.cnt, 2)) as ratio
    from min_cnt, max_cnt;
