def get_throttled_by_provisioned_read_event_percent(
        table_name, lookback_window_start=15, lookback_period=5):
    """ Returns the number of throttled read events in percent

    :type table_name: str
    :param table_name: Name of the DynamoDB table
    :type lookback_window_start: int
    :param lookback_window_start: Relative start time for the CloudWatch metric
    :type lookback_period: int
    :param lookback_period: Number of minutes to look at
    :returns: float -- Percent of throttled read events by provisioning
    """
    try:
        metrics = __get_aws_metric(
            table_name,
            lookback_window_start,
            lookback_period,
            'ReadThrottleEvents')
    except BotoServerError:
        raise

    if metrics:
        lookback_seconds = lookback_period * 60
        throttled_read_events = (
            float(metrics[0]['Sum']) / float(lookback_seconds))
    else:
        throttled_read_events = 0

    try:
        table_read_units = dynamodb.get_provisioned_table_read_units(
            table_name)

        throttled_by_provisioned_read_percent = (
            float(throttled_read_events) /
            float(table_read_units) * 100)
    except JSONResponseError:
        raise

    logger.info('{0} - Throttled read percent by provision: {1:.2f}%'.format(
        table_name, throttled_by_provisioned_read_percent))
    return throttled_by_provisioned_read_percent
Returns the number of throttled read events in percent

    :type table_name: str
    :param table_name: Name of the DynamoDB table
    :type lookback_window_start: int
    :param lookback_window_start: Relative start time for the CloudWatch metric
    :type lookback_period: int
    :param lookback_period: Number of minutes to look at
    :returns: float -- Percent of throttled read events by provisioning