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select count(case when cn<10 then 1 end) as less_10, count(case when (cn>=10 and cn<=20) then 1 end) as large_10_and_less_20, count(case when cn>20 then 1 end) as large_20 from ( select owneruserid, count(*) cn from posts where posttypeid = ( select id from posttypes where name = 'Question' ) group by owneruserid ) as x