From 2018 to 2020, which year did the George Lewis group have the highest number of orders?
George Lewis refers to Sales Team; the highest number of orders refers to MAX(COUNT(OrderNumber)); which year from 2018 to 2020 refers to SUBSTR(OrderDate, -2) IN ('18', '19', '20') GROUP BY SUBSTR(OrderDate, -2);
SELECT SUBSTR(T1.OrderDate, -2, 2) FROM `Sales Orders` AS T1 INNER JOIN `Sales Team` AS T2 ON T2.SalesTeamID = T1._SalesTeamID WHERE T2.`Sales Team` = 'George Lewis' GROUP BY SUBSTR(T1.OrderDate, -2, 2) ORDER BY COUNT(T1.OrderNumber) DESC LIMIT 1