How to determine tables with highest data change rate at Oracle 10G

DBA_HIST_SEG_STAT system view can be used to see physical read-write statistics on segments. Statistics are taken by regular snaps. Following sql script returns tables with higher block change rate, bigger then 20000.

select SNAP_ID,OWNER ,OBJECT_NAME, OBJECT_TYPE, DB_BLOCK_CHANGES_DELTA
from dba_objects a,
(select SNAP_ID,obj#,DB_BLOCK_CHANGES_DELTA from DBA_HIST_SEG_STAT where DB_BLOCK_CHANGES_DELTA > 20000 order by snap_id desc, DB_BLOCK_CHANGES_DELTA desc) b
where a.object_id=b.obj# and object_type='TABLE'
order by snap_id desc, DB_BLOCK_CHANGES_DELTA desc

select c.SNAP_ID,c.END_INTERVAL_TIME SNAP_TIME,a.OWNER ,a.OBJECT_NAME, a.OBJECT_TYPE, b.DB_BLOCK_CHANGES_DELTA
from dba_objects a,
(select SNAP_ID,obj#,DB_BLOCK_CHANGES_DELTA from DBA_HIST_SEG_STAT where DB_BLOCK_CHANGES_DELTA > 20000 order by snap_id desc, DB_BLOCK_CHANGES_DELTA desc) b,
DBA_HIST_SNAPSHOT c
where a.object_id=b.obj# and object_type='TABLE' and b.SNAP_ID=c.SNAP_ID
order by snap_id desc, DB_BLOCK_CHANGES_DELTA desc