condition mean min max ZT0-3 303.076111975 253.30955125000003 352.8426727 ZT4-7 156.51803855 130.62672350000003 182.40935359999997 ZT8-11 102.132345685 98.078250725 106.186440645 ZT12-15 51.25973629 41.326068 61.19340458 ZT16-19 34.41331263 33.759233475 35.067391785 ZT20-23 24.44394475 23.68063658 25.207252920000002