condition mean min max ZT0-3 20.406953333333334 9.58076 26.7568 ZT4-7 6.66123 6.66123 6.66123 ZT8-11 12.7454 12.7454 12.7454 ZT12-15 25.937350000000002 22.472450000000002 29.40225 ZT16-19 28.0705 28.0705 28.0705 ZT20-23 34.4553 34.4553 34.4553