condition mean min max ZT0-3 19.75 19.75 19.75 ZT4-7 1.0 1.0 1.0 ZT8-11 24.849999999999998 24.849999999999998 24.849999999999998 ZT12-15 30.65 30.65 30.65 ZT16-19 5.35 5.35 5.35 ZT20-23 12.15 12.15 12.15