condition mean min max ZT0-3 2.475675 2.13765 2.8137 ZT4-7 1.95932 1.95932 1.95932 ZT8-11 2.75534 2.75534 2.75534 ZT12-15 0 0 0 ZT16-19 3.05147 3.05147 3.05147 ZT20-23 1.496245 1.496245 1.496245