CREATE TABLE table_57290 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Points" FLOAT)

Which year has a total of 0 points and a chassis of Toleman tg181?
SELECT AVG("Year") FROM table_57290 WHERE "Points" = '0' AND "Chassis" = 'toleman tg181'
SELECT AVG("Year") FROM "table_57290" WHERE "Chassis" = 'toleman tg181' AND "Points" = '0'