condition mean min max ZT0-3 9.9 9.9 9.9 ZT4-7 27.8 27.8 27.8 ZT8-11 35.099999999999994 35.099999999999994 35.099999999999994 ZT12-15 29.5 29.5 29.5 ZT16-19 19.55 19.55 19.55 ZT20-23 21.450000000000003 21.450000000000003 21.450000000000003