ESS - Average Completion Run Time Jobs Last Hour

SELECT ROUND(AVG(TO_NUMBER(TO_CHAR(PROCESSEND,'YYYYMMDDHH24MISS')) - TO_NUMBER(TO_CHAR(PROCESSSTART,'YYYYMMDDHH24MISS'))), 2) AS average_seconds 
 FROM FUSION_ORA_ESS.REQUEST_HISTORY 
 WHERE state = 12 
   AND submission > (SELECT SYSDATE - INTERVAL '1' HOUR FROM dual);