def _area_ratio_change(self, area_sum_list):
    ratio_list = []
    for n in range(len(area_sum_list)):
        if (n != 0):
            ratio = (area_sum_list[n] / area_sum_list[(n - 1)])
            ratio_list.append(ratio)
    return ratio_list
def _area_ratio_change(self, area_sum_list):
    ratio_list = []
    for n in range(len(area_sum_list)):
        if (n != 0):
            ratio = (area_sum_list[n] / area_sum_list[(n - 1)])
            ratio_list.append(ratio)
    return ratio_list