condition mean min max ZT0-3 4.1186675 3.99912 4.238215 ZT4-7 6.55321 6.55321 6.55321 ZT8-11 7.807135000000001 7.807135000000001 7.807135000000001 ZT12-15 0 0 0 ZT16-19 8.16128 8.16128 8.16128 ZT20-23 3.4887699999999997 3.4887699999999997 3.4887699999999997