condition mean min max ZT0-3 4.429209999999999 2.83472 6.0237 ZT4-7 3.319065 3.319065 3.319065 ZT8-11 0.466864 0.466864 0.466864 ZT12-15 0 0 0 ZT16-19 4.180275 4.180275 4.180275 ZT20-23 6.069224999999999 6.069224999999999 6.069224999999999