def median_hilow(series, confidence_interval=0.95):
    """
    Median and a selected pair of outer quantiles having equal tail areas
    """
    tail = (1 - confidence_interval) / 2
    return pd.DataFrame({'y': [np.median(series)],
                         'ymin': np.percentile(series, 100 * tail),
                         'ymax': np.percentile(series, 100 * (1 - tail))})
Median and a selected pair of outer quantiles having equal tail areas