condition mean min max ZT0-3 3.2646699999999997 3.2646699999999997 3.2646699999999997 ZT4-7 1.736035 1.736035 1.736035 ZT8-11 1.118675 1.118675 1.118675 ZT12-15 2.177685 2.177685 2.177685 ZT16-19 2.079995 2.079995 2.079995 ZT20-23 2.9399800000000003 2.9399800000000003 2.9399800000000003