select * from
		(
		Select b.gr_sub_cd,
		c.gr_desc,d.prod_nm,
		to_char(a.ro_clo_dt,'MMRRRR') dt,
		count(chasis_no) Tot,
		b.prod_cd,
		row_number() over
				(partition by to_char(a.ro_clo_dt,'MMRRRR') 
				order by to_char(a.ro_clo_dt,'MMRRRR' ) desc) aa
		from ro.ro_mst a,
		sv_pir b,
		sv_pirgroupdtl c,
		sl_prod d
		where a.ro_clo_dt=b.dt_entry(+)
		and b.GR_CD  =c.GR_CD(+)
		and b.prod_cd=d.prod_Cd(+)
		and b.dt_entry(+) between '01JAN08' AND '31DEC08'
		and a.ro_clo_dt between '01JAN08' AND '31DEC08'
		AND B.PROD_CD(+)='12'
		group by to_char(a.ro_clo_dt,'MMRRRR'),
		b.prod_cd,
		b.gr_sub_cd,
		c.gr_desc,
		d.prod_nm,
		to_char(a.ro_clo_dt,'MMRRRR'))
where aa=1