condition mean min max ZT0-3 38.099999999999994 38.099999999999994 38.099999999999994 ZT4-7 5.4 5.4 5.4 ZT8-11 13.5 13.5 13.5 ZT12-15 21.45 21.45 21.45 ZT16-19 43.75 43.75 43.75 ZT20-23 61.7 61.7 61.7