select s.*,
	CASE
	   WHEN rank >= 1 and s.rank <= 10 THEN 1
	   WHEN rank >= 11 and s.rank <= 20  THEN 2
	   WHEN rank >= 21 and s.rank <= 30 THEN 3
	   WHEN rank >= 31 THEN 0
	END as AccountType
	FROM
	(
		SELECT u.ID, @rownum := @rownum + 1 AS rank
		FROM
		Users u,
		(SELECT @rownum := 0) r
		ORDER BY u.AverageROI desc
	) as s