condition mean min max ZT0-3 499.648614 499.648614 499.648614 ZT4-7 879.3513255 879.3513255 879.3513255 ZT8-11 1084.2148535000001 1084.2148535000001 1084.2148535000001 ZT12-15 669.9336205 669.9336205 669.9336205 ZT16-19 679.9522850000001 679.9522850000001 679.9522850000001 ZT20-23 663.435967 663.435967 663.435967