What is the average number of inspections did risk level 3 taverns have?
risk level 3 refers to risk_level = '3'; tavern refers to facility_type = 'TAVERN'; average number = divide(count(inspection_id), sum(license_no)) where risk_level = '3' and facility_type = 'TAVERN'
SELECT CAST(COUNT(T2.inspection_id) AS REAL) / COUNT(DISTINCT T1.license_no) FROM establishment AS T1 INNER JOIN inspection AS T2 ON T1.license_no = T2.license_no WHERE T1.risk_level = 3 AND T1.facility_type = 'TAVERN'