condition mean min max ZT0-3 0.623671 0.623671 0.623671 ZT4-7 0.33758900000000003 0.33758900000000003 0.33758900000000003 ZT8-11 0.24887399999999998 0.24887399999999998 0.24887399999999998 ZT12-15 0.2784765 0.2784765 0.2784765 ZT16-19 0.33782049999999997 0.33782049999999997 0.33782049999999997 ZT20-23 0.7941625 0.7941625 0.7941625