SELECT
    SUM(L_EXTENDEDPRICE) / 7.0 AS AVG_YEARLY
FROM
    LINEITEM,
    PART
WHERE
    P_PARTKEY = L_PARTKEY
    AND P_RETAILPRICE :varies
    AND L_QUANTITY < (
        SELECT
            0.2 * AVG(L_QUANTITY)
        FROM
            LINEITEM
        WHERE
            L_PARTKEY = PART.P_PARTKEY
            AND L_EXTENDEDPRICE :varies
    )