SELECT
  A.val,
  A.rank_over,
  A.percent_rank_over,
  B.rank_4,
  B.percent_rank_4
FROM (
  SELECT
    val,
    RANK() OVER (ORDER BY val ASC) rank_over,
    PERCENT_RANK() OVER (ORDER BY val ASC) percent_rank_over
  FROM (
    SELECT            1 AS val FROM DUAL
    UNION ALL SELECT  2 FROM DUAL
    UNION ALL SELECT  3 FROM DUAL
    UNION ALL SELECT  4 FROM DUAL
    UNION ALL SELECT  5 FROM DUAL
    UNION ALL SELECT  6 FROM DUAL
    UNION ALL SELECT  7 FROM DUAL)
  GROUP BY val) A,
  (
  SELECT
    RANK(4) WITHIN GROUP (ORDER BY val ASC) AS rank_4,
    PERCENT_RANK(4) WITHIN GROUP (ORDER BY val ASC) AS percent_rank_4
  FROM (
    SELECT            1 AS val FROM DUAL
    UNION ALL SELECT  2 FROM DUAL
    UNION ALL SELECT  3 FROM DUAL
    UNION ALL SELECT  4 FROM DUAL
    UNION ALL SELECT  5 FROM DUAL
    UNION ALL SELECT  6 FROM DUAL
    UNION ALL SELECT  7 FROM DUAL)
) B
/

    VAL  RANK_OVER PERCENT_RANK_OVER    RANK_4 PERCENT_RANK_4
------- ---------- ----------------- -------- --------------
      1          1                 0        4     .428571429
      2          2        .166666667        4     .428571429
      3          3        .333333333        4     .428571429
      4          4                .5        4     .428571429
      5          5        .666666667        4     .428571429
      6          6        .833333333        4     .428571429
      7          7                 1        4     .428571429

Aggregate Function

percent_rank = (rank - 1) / (no.of_rows_in_a_group)

Analytic Function

percent_rank = (rank - 1) / (no_of_rows_in_a_partition - 1)