ระยะที่ 4 ถอนตัวกี่คน ?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
how many people withdrew in the 4th stage ?It is not neccessary to use all the tables.
 table_204_530:  id [ number]  "type" [ text]  "stage" [ number]  "cyclist" [ text]  "team" [ text]  "reason" [ text] 
SELECT COUNT("type") FROM table_204_530 WHERE "stage" = 4