CREATE TABLE table_54507 ("Driver" TEXT, "Constructor" TEXT, "Laps" FLOAT, "Time/Retired" TEXT, "Grid" FLOAT)

What are the average laps for jackie stewart?
SELECT AVG("Laps") FROM table_54507 WHERE "Driver" = 'jackie stewart'
SELECT AVG("Laps") FROM "table_54507" WHERE "Driver" = 'jackie stewart'