condition mean min max ZT0-3 4.006185 4.006185 4.006185 ZT4-7 3.5606099999999996 3.5606099999999996 3.5606099999999996 ZT8-11 3.54353 3.54353 3.54353 ZT12-15 3.6716100000000003 3.6716100000000003 3.6716100000000003 ZT16-19 4.381315 4.381315 4.381315 ZT20-23 4.09256 4.09256 4.09256