def norm_min_max_dict(dict1):
    """
    min-max normalization for dictionary
    :param dict1: input dictionary
    :return: min-max normalized dictionary
    """
    for key, value in dict1.items():
        dict1[key] = round((dict1[key] - min(dict1.values())) / (max(dict1.values()) - min(dict1.values())), 3)
    return dict1