condition mean min max ZT0-3 3.2645750000000002 2.18942 3.8499800000000004 ZT4-7 1.75328 1.75328 1.75328 ZT8-11 2.5555849999999998 2.5555849999999998 2.5555849999999998 ZT12-15 3.558475 3.19599 3.92096 ZT16-19 3.7470499999999998 3.7470499999999998 3.7470499999999998 ZT20-23 4.6573 4.6573 4.6573