condition mean min max ZT0-3 1.024539 1.024539 1.024539 ZT4-7 3.5118 3.5118 3.5118 ZT8-11 0.666438 0.666438 0.666438 ZT12-15 0.537318 0.537318 0.537318 ZT16-19 4.611155 4.611155 4.611155 ZT20-23 1.076625 1.076625 1.076625