instruction: For those employees who was hired before 2002-06-21, give me the comparison about the sum of employee_id over the hire_date bin hire_date by time by a bar chart, I want to rank in desc by the sum employee id.
response: SELECT HIRE_DATE, SUM(EMPLOYEE_ID) FROM employees WHERE HIRE_DATE < '2002-06-21' ORDER BY SUM(EMPLOYEE_ID) DESC