CREATE TABLE table_name_50 (laps INTEGER, driver VARCHAR)
SELECT AVG(laps) FROM table_name_50 WHERE driver = "piero taruffi"
จำนวนรอบเฉลี่ยของนักแข่ง Piero Taruffi คือเท่าไร?
What is the average number of laps for the driver Piero Taruffi?