เอสโตริลเปิดได้นานแค่ไหน ?ไม่จำเป็นต้องใช้ทุกโต๊ะ
how long did the estoril open last ?It is not neccessary to use all the tables.
 table_204_85:  id [ number]  "dates" [ text]  "tournament" [ text]  "winner" [ text]  "notes" [ text] 
SELECT "dates" - "dates" FROM table_204_85 WHERE "tournament" = 'estoril open'