instruction: For those employees who was hired before 2002-06-21, give me the comparison about the amount of job_id over the job_id , and group by attribute job_id, and list from low to high by the x-axis.
response: SELECT JOB_ID, COUNT(JOB_ID) FROM employees WHERE HIRE_DATE < '2002-06-21' GROUP BY JOB_ID ORDER BY JOB_ID