condition mean min max ZT0-3 0.657814 0.657814 0.657814 ZT4-7 0.894729 0.894729 0.894729 ZT8-11 1.486015 1.486015 1.486015 ZT12-15 2.459075 2.459075 2.459075 ZT16-19 2.8461600000000002 2.8461600000000002 2.8461600000000002 ZT20-23 0.9919929999999999 0.9919929999999999 0.9919929999999999