CREATE TABLE table_15835 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Points" TEXT)

What year did Elf Team Tyrrell have 34 points?
SELECT AVG("Year") FROM table_15835 WHERE "Entrant" = 'elf team tyrrell' AND "Points" = '34'
SELECT AVG("Year") FROM "table_15835" WHERE "Entrant" = 'elf team tyrrell' AND "Points" = '34'