SELECT CASE WHEN MONTH(t.transaction_date) IN (12,1,2) THEN "Winter" WHEN MONTH(t.transaction_date) IN (3,4,5) THEN "Spring" WHEN MONTH(t.transaction_date) IN (6,7,8) THEN "Summer" ELSE "Fall" END season,COUNT(DISTINCT t.contact_id) customers,COUNT(t.id) transactions FROM transactions t WHERE t.type="sell" GROUP BY 1 ORDER BY customers DESC;