UPDATE scores
SET score = CASE WHEN (student_code = 'A00016' OR student_code = 'A00095') AND (score BETWEEN 96 AND 99) 
THEN 100 ELSE SCORE END ;

UPDATE scores
SET score = CASE WHEN (student_code = 'A00016' OR student_code = 'A00095') AND (score BETWEEN 0 AND 95) 
THEN score + 5  ELSE SCORE END ;

SELECT * FROM SCORES;