@staticmethod
def score_c_to_5_classes(score_c):
    """
        Score C to 5 risk-classes

        :param score_c:  Score C
        :return: Risk-class
        """
    if score_c == 1:
        ret = 0
    elif 2 <= score_c <= 3:
        ret = 1
    elif 4 <= score_c <= 7:
        ret = 2
    elif 8 <= score_c <= 10:
        ret = 3
    else:
        ret = 4
    return ret
