def none_low_med_high_to_value(scale_value):
    """
    This method will transform a string value from the None / Low / Med /
    High scale to its confidence integer representation.

    The scale for this confidence representation is the following:

    .. list-table:: None, Low, Med, High to STIX Confidence
        :header-rows: 1

        * - None/ Low/ Med/ High
          - STIX Confidence Value
        * - Not Specified
          - Not Specified
        * - None
          - 0
        * - Low
          - 15
        * - Med
          - 50
        * - High
          - 85

    Args:
        scale_value (str): A string value from the scale. Accepted strings are
            "None", "Low", "Med" and "High". Argument is case sensitive.

    Returns:
        int: The numerical representation corresponding to values in the
            None / Low / Med / High scale.

    Raises:
        ValueError: If `scale_value` is not within the accepted strings.
    """
    if scale_value == 'None':
        return 0
    elif scale_value == 'Low':
        return 15
    elif scale_value == 'Med':
        return 50
    elif scale_value == 'High':
        return 85
    else:
        raise ValueError("STIX Confidence value cannot be determined for %s" % scale_value)