condition mean min max ZT0-3 4.051853333333333 1.89202 8.111699999999999 ZT4-7 3.45692 3.45692 3.45692 ZT8-11 1.447335 1.447335 1.447335 ZT12-15 1.8213525 1.508025 2.13468 ZT16-19 1.73139 1.73139 1.73139 ZT20-23 1.72861 1.72861 1.72861