script to track oracle growth

select b.tsname tablespace_name , MAX(b.used_size_mb) cur_used_size_mb , round(AVG(inc_used_size_mb),2)avg_increas_mb  from  ( SELECT a.days,a.tsname , used_size_mb , used_size_mb - LAG (used_size_mb,1) OVER ( PARTITION BY a.tsname ORDER BY a.tsname,a.days) inc_used_size_mb
   from ( SELECT TO_CHAR(sp.begin_interval_time,'MM-DD-YYYY') days  ,ts.tsname ,MAX(round((tsu.tablespace_usedsize* dt.block_size )/(1024*1024),2)) used_size_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 sp.begin_interval_time > sysdate-7
    GROUP BY TO_CHAR(sp.begin_interval_time,'MM-DD-YYYY'), ts.tsname
    ORDER BY ts.tsname, days ) a
    ) b GROUP BY b.tsname ORDER BY b.tsname;