condition mean min max ZT0-3 2.9593921666666665 1.0392565 6.115345 ZT4-7 2.85886 2.85886 2.85886 ZT8-11 3.04779 3.04779 3.04779 ZT12-15 2.411595 1.5248249999999999 3.298365 ZT16-19 1.13032 1.13032 1.13032 ZT20-23 0.6697040000000001 0.6697040000000001 0.6697040000000001