condition mean min max ZT0-3 0.872649 0.6816305 1.0636675 ZT4-7 1.32329 1.32329 1.32329 ZT8-11 0.842654 0.842654 0.842654 ZT12-15 0 0 0 ZT16-19 1.9718200000000001 1.9718200000000001 1.9718200000000001 ZT20-23 1.22747 1.22747 1.22747