condition mean min max ZT0-3 1.5626846666666667 0.9559040000000001 1.9116849999999999 ZT4-7 0.804717 0.804717 0.804717 ZT8-11 0.8085675 0.8085675 0.8085675 ZT12-15 2.5605599999999997 1.5128949999999999 3.608225 ZT16-19 2.5791950000000003 2.5791950000000003 2.5791950000000003 ZT20-23 2.074105 2.074105 2.074105