condition mean min max ZT0-3 2.1483398333333334 0.7464895 2.9805849999999996 ZT4-7 2.600335 2.600335 2.600335 ZT8-11 4.431255 4.431255 4.431255 ZT12-15 3.74729 3.34687 4.14771 ZT16-19 5.37396 5.37396 5.37396 ZT20-23 4.527445 4.527445 4.527445