condition mean min max ZT0-3 9.549999999999999 9.549999999999999 9.549999999999999 ZT4-7 13.0 13.0 13.0 ZT8-11 28.55 28.55 28.55 ZT12-15 49.099999999999994 49.099999999999994 49.099999999999994 ZT16-19 30.2 30.2 30.2 ZT20-23 30.75 30.75 30.75