CASE WHEN(
  (%CC0570%* 100)/%CC5751%
) < 30 THEN "Normal (Less than 30 mg/g)"

WHEN (
  (%CC0570%* 100)/%CC5751%
) >= 30 
AND %CC5752% < 300 THEN "Abnormal (Between 30-300 mg/g)"
WHEN (
  (%CC0570%* 100)/%CC5751%
) > 300 THEN "Abnormal (More than 300 mg/g)" 

ELSE "Error"
END