condition mean min max ZT0-3 18.75 18.75 18.75 ZT4-7 29.0 29.0 29.0 ZT8-11 4.449999999999999 4.449999999999999 4.449999999999999 ZT12-15 47.099999999999994 47.099999999999994 47.099999999999994 ZT16-19 25.25 25.25 25.25 ZT20-23 8.25 8.25 8.25