instruction: List the number of enginners and group by last name in a bar chart, sort in asc by the bar.
response: SELECT last_name, COUNT(last_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 last_name ORDER BY last_name