condition mean min max ZT0-3 24.299999999999997 24.299999999999997 24.299999999999997 ZT4-7 23.9 23.9 23.9 ZT8-11 33.400000000000006 33.400000000000006 33.400000000000006 ZT12-15 31.95 31.95 31.95 ZT16-19 27.15 27.15 27.15 ZT20-23 18.75 18.75 18.75