CREATE TABLE table_59630 ("Round" TEXT, "Date" TEXT, "Event" TEXT, "Circuit" TEXT, "Winning Driver" TEXT, "Winning Team" TEXT)

Who was the winning team on May 12?
SELECT "Winning Team" FROM table_59630 WHERE "Date" = 'may 12'
SELECT "Winning Team" FROM "table_59630" WHERE "Date" = 'may 12'