日期前五年后五年ORACLE

SELECT EXTRACT(YEAR FROM SYSDATE) + LEVEL||'年' AS year, EXTRACT(YEAR FROM SYSDATE) + LEVEL as nian
  FROM DUAL
CONNECT BY LEVEL <=5
UNION
 SELECT EXTRACT(YEAR FROM SYSDATE)||'年' AS year,EXTRACT(YEAR FROM SYSDATE) as nian
 FROM DUAL
CONNECT BY LEVEL = 0
UNION
SELECT EXTRACT(YEAR FROM SYSDATE) - LEVEL||'年' AS year,EXTRACT(YEAR FROM SYSDATE) - LEVEL as nian
  FROM DUAL
CONNECT BY LEVEL <= 5