WITH SIZE AS (SELECT ID,
              NTILE(4) OVER (ORDER BY SIZE_OF_COLONY DESC) AS GRADE
                FROM ECOLI_DATA 
                ORDER BY SIZE_OF_COLONY DESC)
                
SELECT E.ID,
        CASE WHEN (GRADE = 1) THEN 'CRITICAL'
              WHEN (GRADE = 2) THEN 'HIGH'
              WHEN (GRADE = 3) THEN 'MEDIUM'
              ELSE 'LOW'
             END AS COLONY_NAME
FROM ECOLI_DATA AS E RIGHT JOIN SIZE AS S
ON E.ID = S.ID
ORDER BY E.ID