ตารางที่ 21 มีกี่รอบ?ไม่จำเป็นต้องใช้ตารางทั้งหมด
How many laps were there in grid 21?It is not neccessary to use all the tables.
 table_78318:  "Driver" [ text]  "Constructor" [ text]  "Laps" [ text]  "Time/Retired" [ text]  "Grid" [ text] 
SELECT "Laps" FROM table_78318 WHERE "Grid" = '21'