mariadb/scripts/atc.ontime/q5.sql

SELECT t.carrier, c, c2, c*1000/c2 as c3 FROM (SELECT carrier, count(*) AS c FROM ontime WHERE DepDelay>10 AND Year=2007 GROUP BY carrier) t JOIN (SELECT carrier, count(*) AS c2 FROM ontime WHERE Year=2007 GROUP BY carrier) t2 ON (t.Carrier=t2.Carrier) ORDER BY c3 DESC;