Oracle 10g Estimate Tablespace growth

set pagesize 200
col tsname format a20

SELECT TO_CHAR (sp.begin_interval_time,'DD-MM-YYYY') days
, ts.tsname
, max(round((tsu.tablespace_size* dt.block_size )/(1024*1024),2) ) cur_size_MB
, max(round((tsu.tablespace_usedsize* dt.block_size )/(1024*1024),2)) usedsize_MB
FROM DBA_HIST_TBSPC_SPACE_USAGE tsu
, DBA_HIST_TABLESPACE_STAT ts
, DBA_HIST_SNAPSHOT sp
, DBA_TABLESPACES dt
WHERE tsu.tablespace_id= ts.ts#
AND tsu.snap_id = sp.snap_id
AND ts.tsname = dt.tablespace_name
AND ts.tsname NOT IN ('SYSAUX','SYSTEM')
GROUP BY TO_CHAR (sp.begin_interval_time,'DD-MM-YYYY'), ts.tsname
ORDER BY ts.tsname, days;