Average growth over the past 12 months

     SELECT
       (max(round(avg(a_size.size_gb),2)) - min(round(avg(a_size.size_gb),2)))/12
     FROM
      (SELECT  
           m.rollup_timestamp AS month_timestamp,
           sum(m.average/1024) AS size_gb
         FROM 
           mgmt$metric_daily m,
           mgmt$target_type t
         WHERE 
           t.target_guid=HEXTORAW('A06F734DEB35E1CFE38C9AB4729508E2') AND
           (t.target_type='rac_database' OR 
           (t.target_type='oracle_database' AND t.TYPE_QUALIFIER3 != 'RACINST')) AND      
           m.target_guid=t.target_guid AND
           m.metric_guid=t.metric_guid AND
           t.metric_name='tbspAllocation' AND
           (t.metric_column='spaceAllocated') AND
           m.rollup_timestamp >= sysdate-365 AND
           m.rollup_timestamp <= sysdate
         GROUP BY m.metric_column, m.rollup_timestamp) a_size,
       (SELECT  
           m.rollup_timestamp AS month_timestamp,
           sum(m.average/1024) AS used_gb
         FROM 
           mgmt$metric_daily m,
           mgmt$target_type t
         WHERE 
           t.target_guid=HEXTORAW('A06F734DEB35E1CFE38C9AB4729508E2') AND
           (t.target_type='rac_database' OR 
           (t.target_type='oracle_database' AND t.TYPE_QUALIFIER3 != 'RACINST')) AND      
           m.target_guid=t.target_guid AND
           m.metric_guid=t.metric_guid AND
           t.metric_name='tbspAllocation' AND
           (t.metric_column='spaceUsed') AND
           m.rollup_timestamp >= sysdate-365 AND
           m.rollup_timestamp <= sysdate
         GROUP BY m.metric_column, m.rollup_timestamp) used
     WHERE
       a_size.month_timestamp =used.month_timestamp
     GROUP BY TO_CHAR(a_size.month_timestamp,'MON RR');