CREATE TABLE table_56369 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Pts." FLOAT)

In what year did a car have a yamaha v12 engine and a brabham bt60y chassis
SELECT "Year" FROM table_56369 WHERE "Engine" = 'yamaha v12' AND "Chassis" = 'brabham bt60y'
SELECT "Year" FROM "table_56369" WHERE "Chassis" = 'brabham bt60y' AND "Engine" = 'yamaha v12'