CREATE TABLE table_38678 ("Make" TEXT, "Year placed in service" TEXT, "Quantity" FLOAT, "Number of seats" FLOAT, "Wheelchair accessible?  (  ) " TEXT, "Current status" TEXT)

What is the smallest number of seats in a retired vehicle that was started in service in 1981?
SELECT MIN("Number of seats") FROM table_38678 WHERE "Current status" = 'retired' AND "Year placed in service" = '1981'
SELECT MIN("Number of seats") FROM "table_38678" WHERE "Current status" = 'retired' AND "Year placed in service" = '1981'