SELECT ex, lv, tt, td, trex, sum(uq) as uq FROM
( SELECT ex.ex, ex.lv, ex.tt, ex.td, dn2.ex AS trex, round(avg(ap.uq)) as uq
  FROM ex
  INNER JOIN lv ON (lv.lv = ex.lv)
  INNER JOIN dn ON (dn.ex = ex.ex)
  INNER JOIN dn AS dn2 ON (dn2.mn = dn.mn)
  INNER JOIN mn ON (mn.mn = dn.mn)
  INNER JOIN ap ON (ap.ap = mn.ap)
  WHERE
    lcvc(lv.lc, lv.vc) IN ('eng-000') AND
    dn.ex != dn2.ex AND
    dn2.ex IN (74)
  GROUP BY ex.ex, ex.lv, ex.tt, ex.td, dn2.ex, ap.ui
) s
GROUP BY ex, lv, tt, td, trex
ORDER BY ex, uq
LIMIT 2000;