DECLARE

 YEAR NUMBER;

BEGIN

DELETE FROM HISTORY_SUM;

INSERT INTO HISTORY_SUM (YEAR)

Select DISTINCT(TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY'))) as YEAR from HISTORY

ORDER BY YEAR;

     FOR x IN (Select * from HISTORY_SUM) LOOP

     UPDATE HISTORY_SUM

     SET JAN = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 1)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET FEB = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 2)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET MAR = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 3)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET APR = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 4)

     WHERE YEAR = x.YEAR;     

     UPDATE HISTORY_SUM

     SET MAY = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 5)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET JUN = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 6)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET JUL = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 7)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET AUG = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 8)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET SEP = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 9)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET OCT = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 10)

     WHERE YEAR = x.YEAR;     

     UPDATE HISTORY_SUM

     SET NOV = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 11)

     WHERE YEAR = x.YEAR;

     UPDATE HISTORY_SUM

     SET DEC = (Select SUM(TOTAL_$) from HISTORY c

WHERE TO_NUMBER(TO_CHAR(VISIT_DATE, 'YYYY')) = YEAR AND TO_NUMBER(TO_CHAR(VISIT_DATE, 'MM')) = 12)

     WHERE YEAR = x.YEAR;

  END LOOP;    

COMMIT;

END;