instruction: List the number of enginners and group by first name in a bar chart, and rank by the bars from low to high.
response: SELECT first_name, COUNT(first_name) FROM Maintenance_Engineers AS T1 JOIN Engineer_Skills AS T2 ON T1.engineer_id = T2.engineer_id JOIN Skills AS T3 ON T2.skill_id = T3.skill_id GROUP BY first_name ORDER BY first_name