select mon, arbid, sum(erstPag#), sum(erstCou#)
from
(select
year(ldatum) * 100 + month(lDatum) as mon,
left(erstJob,4) arbid,
erstPag#,
erstCou#
from $DBOWNER.vpv013a1a
where mandant = '0034'
and left(erstJob,2)
in ('W0', 'W1', 'W2', 'W3', 'W4', 'W5')
and lDatum between '${MONTH}01' and '${MONTH}31'
) t1
group by arbid , mon
order by arbid desc, mon