SELECT *, 100 * dwindle / total `percentage`
	FROM (
		SELECT u.name buyer,
				SUM(saleTotal) total,
				SUM(w.saleInternalWaste + w.saleExternalWaste) dwindle
			FROM bs.waste w
				JOIN account.user u ON u.id = w.buyerFk
				JOIN vn.itemType it ON it.id = w.itemTypeFk
			WHERE w.year = YEAR(util.VN_CURDATE() - INTERVAL 1 WEEK)
				AND w.week = WEEK(util.VN_CURDATE() - INTERVAL 1 WEEK, 4)
			GROUP BY buyerFk
		) sub
		ORDER BY `percentage` DESC;