What is the average number of inspections done by the top 5 employees with the highest salary? List the names of the said employees.
the highest salary refers to max(salary); sanitarian refers to title = 'Sanitarian'; name refers to first_name, last_name; average number = divide(sum(inspection_id), 5)
SELECT CAST(COUNT(DISTINCT T2.inspection_id) AS REAL) / 5, T1.first_name, T1.last_name FROM employee AS T1 INNER JOIN inspection AS T2 ON T1.employee_id = T2.employee_id WHERE T1.title = 'Sanitarian' ORDER BY T1.salary DESC LIMIT 5