def calculate_relative_metric(curr_score, best_score):
    """
    Calculate the difference between the best score and the current score, as a percentage
    relative to the best score.

    A negative result indicates that the current score is lower (=better) than the best score

    Parameters
    ----------
    curr_score : float
        The current score
    best_score : float
        The best score

    Returns
    -------
    float
        The relative score in percent
    """
    return (100 / best_score) * (curr_score-best_score)