condition mean min max ZT0-3 1.6568224999999999 1.574995 1.7386499999999998 ZT4-7 2.09212 2.09212 2.09212 ZT8-11 2.0903549999999997 2.0903549999999997 2.0903549999999997 ZT12-15 0 0 0 ZT16-19 3.2142 3.2142 3.2142 ZT20-23 1.6518 1.6518 1.6518