For each distinct test result, find the number of students who got the result.
SELECT test_result ,  COUNT(*) FROM Student_Tests_Taken GROUP BY test_result ORDER BY COUNT(*) DESC
SELECT test_result ,  COUNT(*) FROM Student_Tests_Taken GROUP BY test_result ORDER BY COUNT(*) DESC
[{'test_result': 'Pass', 'COUNT(*)': 8}, {'test_result': 'Fail', 'COUNT(*)': 7}]