condition mean min max ZT0-3 39.554525 34.9096 44.19945 ZT4-7 38.4286 38.4286 38.4286 ZT8-11 59.4702 59.4702 59.4702 ZT12-15 0 0 0 ZT16-19 69.2752 69.2752 69.2752 ZT20-23 50.331199999999995 50.331199999999995 50.331199999999995