CREATE TABLE table_204_604 (id DECIMAL, "year" DECIMAL, "date" TEXT, "driver" TEXT, "team" TEXT, "manufacturer" TEXT, "race distance\ laps" DECIMAL, "race distance\ miles  ( km ) " TEXT, "race time" TEXT, "average speed\ ( mph ) " DECIMAL, "report" TEXT)

which manufacturer has the most number of wins at the auto club 400 between 1997 and 2014 ?
SELECT "manufacturer" FROM table_204_604 GROUP BY "manufacturer" ORDER BY COUNT(*) DESC LIMIT 1
SELECT "manufacturer" FROM "table_204_604" GROUP BY "manufacturer" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1